[SPARK-18446][ML][DOCS] Add links to API docs for ML algos

## What changes were proposed in this pull request?
Add links to API docs for ML algos
## How was this patch tested?
Manual checking for the API links

Author: Zheng RuiFeng <ruifengz@foxmail.com>

Closes #15890 from zhengruifeng/algo_link.

docs/ml-classification-regression.md

@@ -55,14 +55,23 @@ $\alpha$ and `regParam` corresponds to $\lambda$.
 <div class="codetabs">
 
 <div data-lang="scala" markdown="1">
+
+More details on parameters can be found in the [Scala API documentation](api/scala/index.html#org.apache.spark.ml.classification.LogisticRegression).
+
 {% include_example scala/org/apache/spark/examples/ml/LogisticRegressionWithElasticNetExample.scala %}
 </div>
 
 <div data-lang="java" markdown="1">
+
+More details on parameters can be found in the [Java API documentation](api/java/org/apache/spark/ml/classification/LogisticRegression.html).
+
 {% include_example java/org/apache/spark/examples/ml/JavaLogisticRegressionWithElasticNetExample.java %}
 </div>
 
 <div data-lang="python" markdown="1">
+
+More details on parameters can be found in the [Python API documentation](api/python/pyspark.ml.html#pyspark.ml.classification.LogisticRegression).
+
 {% include_example python/ml/logistic_regression_with_elastic_net.py %}
 </div>
 
@@ -289,14 +298,23 @@ MLPC employs backpropagation for learning the model. We use the logistic loss fu
 <div class="codetabs">
 
 <div data-lang="scala" markdown="1">
+
+Refer to the [Scala API docs](api/scala/index.html#org.apache.spark.ml.classification.MultilayerPerceptronClassifier) for more details.
+
 {% include_example scala/org/apache/spark/examples/ml/MultilayerPerceptronClassifierExample.scala %}
 </div>
 
 <div data-lang="java" markdown="1">
+
+Refer to the [Java API docs](api/java/org/apache/spark/ml/classification/MultilayerPerceptronClassifier.html) for more details.
+
 {% include_example java/org/apache/spark/examples/ml/JavaMultilayerPerceptronClassifierExample.java %}
 </div>
 
 <div data-lang="python" markdown="1">
+
+Refer to the [Python API docs](api/python/pyspark.ml.html#pyspark.ml.classification.MultilayerPerceptronClassifier) for more details.
+
 {% include_example python/ml/multilayer_perceptron_classification.py %}
 </div>
 
@@ -392,15 +410,24 @@ regression model and extracting model summary statistics.
 <div class="codetabs">
 
 <div data-lang="scala" markdown="1">
+
+More details on parameters can be found in the [Scala API documentation](api/scala/index.html#org.apache.spark.ml.regression.LinearRegression).
+
 {% include_example scala/org/apache/spark/examples/ml/LinearRegressionWithElasticNetExample.scala %}
 </div>
 
 <div data-lang="java" markdown="1">
+
+More details on parameters can be found in the [Java API documentation](api/java/org/apache/spark/ml/regression/LinearRegression.html).
+
 {% include_example java/org/apache/spark/examples/ml/JavaLinearRegressionWithElasticNetExample.java %}
 </div>
 
 <div data-lang="python" markdown="1">
 <!--- TODO: Add python model summaries once implemented -->
+
+More details on parameters can be found in the [Python API documentation](api/python/pyspark.ml.html#pyspark.ml.regression.LinearRegression).
+
 {% include_example python/ml/linear_regression_with_elastic_net.py %}
 </div>
 
@@ -519,18 +546,21 @@ function and extracting model summary statistics.
 <div class="codetabs">
 
 <div data-lang="scala" markdown="1">
+
 Refer to the [Scala API docs](api/scala/index.html#org.apache.spark.ml.regression.GeneralizedLinearRegression) for more details.
 
 {% include_example scala/org/apache/spark/examples/ml/GeneralizedLinearRegressionExample.scala %}
 </div>
 
 <div data-lang="java" markdown="1">
+
 Refer to the [Java API docs](api/java/org/apache/spark/ml/regression/GeneralizedLinearRegression.html) for more details.
 
 {% include_example java/org/apache/spark/examples/ml/JavaGeneralizedLinearRegressionExample.java %}
 </div>
 
 <div data-lang="python" markdown="1">
+
 Refer to the [Python API docs](api/python/pyspark.ml.html#pyspark.ml.regression.GeneralizedLinearRegression) for more details.
 
 {% include_example python/ml/generalized_linear_regression_example.py %}
@@ -705,14 +735,23 @@ The implementation matches the result from R's survival function
 <div class="codetabs">
 
 <div data-lang="scala" markdown="1">
+
+Refer to the [Scala API docs](api/scala/index.html#org.apache.spark.ml.regression.AFTSurvivalRegression) for more details.
+
 {% include_example scala/org/apache/spark/examples/ml/AFTSurvivalRegressionExample.scala %}
 </div>
 
 <div data-lang="java" markdown="1">
+
+Refer to the [Java API docs](api/java/org/apache/spark/ml/regression/AFTSurvivalRegression.html) for more details.
+
 {% include_example java/org/apache/spark/examples/ml/JavaAFTSurvivalRegressionExample.java %}
 </div>
 
 <div data-lang="python" markdown="1">
+
+Refer to the [Python API docs](api/python/pyspark.ml.html#pyspark.ml.regression.AFTSurvivalRegression) for more details.
+
 {% include_example python/ml/aft_survival_regression.py %}
 </div>
 

docs/ml-pipeline.md

@@ -207,14 +207,29 @@ This example covers the concepts of `Estimator`, `Transformer`, and `Param`.
 <div class="codetabs">
 
 <div data-lang="scala">
+
+Refer to the [`Estimator` Scala docs](api/scala/index.html#org.apache.spark.ml.Estimator),
+the [`Transformer` Scala docs](api/scala/index.html#org.apache.spark.ml.Transformer) and
+the [`Params` Scala docs](api/scala/index.html#org.apache.spark.ml.param.Params) for details on the API.
+
 {% include_example scala/org/apache/spark/examples/ml/EstimatorTransformerParamExample.scala %}
 </div>
 
 <div data-lang="java">
+
+Refer to the [`Estimator` Java docs](api/java/org/apache/spark/ml/Estimator.html),
+the [`Transformer` Java docs](api/java/org/apache/spark/ml/Transformer.html) and
+the [`Params` Java docs](api/java/org/apache/spark/ml/param/Params.html) for details on the API.
+
 {% include_example java/org/apache/spark/examples/ml/JavaEstimatorTransformerParamExample.java %}
 </div>
 
 <div data-lang="python">
+
+Refer to the [`Estimator` Python docs](api/python/pyspark.ml.html#pyspark.ml.Estimator),
+the [`Transformer` Python docs](api/python/pyspark.ml.html#pyspark.ml.Transformer) and
+the [`Params` Python docs](api/python/pyspark.ml.html#pyspark.ml.param.Params) for more details on the API.
+
 {% include_example python/ml/estimator_transformer_param_example.py %}
 </div>
 
@@ -227,14 +242,24 @@ This example follows the simple text document `Pipeline` illustrated in the figu
 <div class="codetabs">
 
 <div data-lang="scala">
+
+Refer to the [`Pipeline` Scala docs](api/scala/index.html#org.apache.spark.ml.Pipeline) for details on the API.
+
 {% include_example scala/org/apache/spark/examples/ml/PipelineExample.scala %}
 </div>
 
 <div data-lang="java">
+
+
+Refer to the [`Pipeline` Java docs](api/java/org/apache/spark/ml/Pipeline.html) for details on the API.
+
 {% include_example java/org/apache/spark/examples/ml/JavaPipelineExample.java %}
 </div>
 
 <div data-lang="python">
+
+Refer to the [`Pipeline` Python docs](api/python/pyspark.ml.html#pyspark.ml.Pipeline) for more details on the API.
+
 {% include_example python/ml/pipeline_example.py %}
 </div>
 

docs/ml-tuning.md

@@ -75,15 +75,23 @@ However, it is also a well-established method for choosing parameters which is m
 <div class="codetabs">
 
 <div data-lang="scala">
+
+Refer to the [`CrossValidator` Scala docs](api/scala/index.html#org.apache.spark.ml.tuning.CrossValidator) for details on the API.
+
 {% include_example scala/org/apache/spark/examples/ml/ModelSelectionViaCrossValidationExample.scala %}
 </div>
 
 <div data-lang="java">
+
+Refer to the [`CrossValidator` Java docs](api/java/org/apache/spark/ml/tuning/CrossValidator.html) for details on the API.
+
 {% include_example java/org/apache/spark/examples/ml/JavaModelSelectionViaCrossValidationExample.java %}
 </div>
 
 <div data-lang="python">
 
+Refer to the [`CrossValidator` Python docs](api/python/pyspark.ml.html#pyspark.ml.tuning.CrossValidator) for more details on the API.
+
 {% include_example python/ml/cross_validator.py %}
 </div>
 
@@ -107,14 +115,23 @@ Like `CrossValidator`, `TrainValidationSplit` finally fits the `Estimator` using
 <div class="codetabs">
 
 <div data-lang="scala" markdown="1">
+
+Refer to the [`TrainValidationSplit` Scala docs](api/scala/index.html#org.apache.spark.ml.tuning.TrainValidationSplit) for details on the API.
+
 {% include_example scala/org/apache/spark/examples/ml/ModelSelectionViaTrainValidationSplitExample.scala %}
 </div>
 
 <div data-lang="java" markdown="1">
+
+Refer to the [`TrainValidationSplit` Java docs](api/java/org/apache/spark/ml/tuning/TrainValidationSplit.html) for details on the API.
+
 {% include_example java/org/apache/spark/examples/ml/JavaModelSelectionViaTrainValidationSplitExample.java %}
 </div>
 
 <div data-lang="python">
+
+Refer to the [`TrainValidationSplit` Python docs](api/python/pyspark.ml.html#pyspark.ml.tuning.TrainValidationSplit) for more details on the API.
+
 {% include_example python/ml/train_validation_split.py %}
 </div>