### What changes were proposed in this pull request?
This PR proposes to switch `pygments.rb`, which only support Python 2 and seems inactive for the last few years (https://github.com/tmm1/pygments.rb), to Rouge which is pure Ruby code highlighter that is compatible with Pygments.
I thought it would be pretty difficult to change but thankfully Rouge does a great job as the alternative.
### Why are the changes needed?
We're moving to Python 3 and drop Python 2 completely.
### Does this PR introduce any user-facing change?
Maybe a little bit of different syntax style but should not have a notable change.
### How was this patch tested?
Manually tested the build and checked the documentation.
Closes#26521 from HyukjinKwon/SPARK-28752.
Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
## What changes were proposed in this pull request?
Easy fix in the documentation.
## How was this patch tested?
N/A
Closes#20948
Author: Daniel Sakuma <dsakuma@gmail.com>
Closes#20928 from dsakuma/fix_typo_configuration_docs.
If a custom Jekyll template tag throws Ruby's equivalent of a "file not found" exception, then Jekyll will stop the doc building process but will exit with a successful status, causing our doc publishing jobs to silently fail.
This is caused by https://github.com/jekyll/jekyll/issues/5104, a case of bad error-handling logic in Jekyll. This patch works around this by updating our `include_example.rb` plugin to catch the exception and exit rather than allowing it to bubble up and be ignored by Jekyll.
I tested this manually with
```
rm ./examples/src/main/scala/org/apache/spark/examples/sql/SparkSQLExample.scala
cd docs
SKIP_API=1 jekyll build
echo $?
```
Author: Josh Rosen <joshrosen@databricks.com>
Closes#14209 from JoshRosen/fix-doc-building.
## What changes were proposed in this pull request?
This PR adds labelling support for the `include_example` Jekyll plugin, so that we may split a single source file into multiple line blocks with different labels, and include them in multiple code snippets in the generated HTML page.
## How was this patch tested?
Manually tested.
<img width="923" alt="screenshot at jun 29 19-53-21" src="https://cloud.githubusercontent.com/assets/230655/16451099/66a76db2-3e33-11e6-84fb-63104c2f0688.png">
Author: Cheng Lian <lian@databricks.com>
Closes#13972 from liancheng/include-example-with-labels.
The trim_codeblock(lines) function in include_example.rb removes some blank lines in the code.
Author: Xusen Yin <yinxusen@gmail.com>
Closes#9400 from yinxusen/SPARK-11443.
A POC code for making example code in user guide testable.
mengxr We still need to talk about the labels in code.
Author: Xusen Yin <yinxusen@gmail.com>
Closes#9109 from yinxusen/SPARK-10382.
