### What changes were proposed in this pull request?
Remove the unneeded embedded inline HTML markup by using the basic markdown syntax.
Please see #28414
### Why are the changes needed?
Make the doc cleaner and easily editable by MD editors.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Manually build and check
Closes#28451 from huaxingao/html_cleanup.
Authored-by: Huaxin Gao <huaxing@us.ibm.com>
Signed-off-by: Sean Owen <srowen@gmail.com>
### What changes were proposed in this pull request?
Fixed typo in `docs` directory and in `project/MimaExcludes.scala`
### Why are the changes needed?
Better readability of documents
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
No test needed
Closes#28447 from kiszk/typo_20200504.
Authored-by: Kazuaki Ishizaki <ishizaki@jp.ibm.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Document Spark integration with Hive UDFs/UDAFs/UDTFs
### Why are the changes needed?
To make SQL Reference complete
### Does this PR introduce any user-facing change?
Yes
<img width="1031" alt="Screen Shot 2020-04-02 at 2 22 42 PM" src="https://user-images.githubusercontent.com/13592258/78301971-cc7cf080-74ee-11ea-93c8-7d4c75213b47.png">
### How was this patch tested?
Manually build and check
Closes#28104 from huaxingao/hive-udfs.
Lead-authored-by: Huaxin Gao <huaxing@us.ibm.com>
Co-authored-by: Takeshi Yamamuro <yamamuro@apache.org>
Signed-off-by: Sean Owen <srowen@gmail.com>