### What changes were proposed in this pull request?
Update trasform's doc to latest code.
![image](https://user-images.githubusercontent.com/46485123/126175747-672cccbc-4e42-440f-8f1e-f00b6dc1be5f.png)
### Why are the changes needed?
keep consistence
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
No
Closes#33362 from AngersZhuuuu/SPARK-36153.
Lead-authored-by: Angerszhuuuu <angers.zhu@gmail.com>
Co-authored-by: AngersZhuuuu <angers.zhu@gmail.com>
Signed-off-by: Sean Owen <srowen@gmail.com>
### What changes were proposed in this pull request?
Extract common doc about hive format for `sql-ref-syntax-ddl-create-table-hiveformat.md` and `sql-ref-syntax-qry-select-transform.md` to refer.
![image](https://user-images.githubusercontent.com/46485123/115802193-04641800-a411-11eb-827d-d92544881842.png)
### Why are the changes needed?
Improve doc
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Not need
Closes#32264 from AngersZhuuuu/SPARK-35159.
Authored-by: Angerszhuuuu <angers.zhu@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
### What changes were proposed in this pull request?
Add doc about `TRANSFORM` and related function.
![image](https://user-images.githubusercontent.com/46485123/114332579-1627fe80-9b79-11eb-8fa7-131f0a20f72f.png)
### Why are the changes needed?
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Not need
Closes#31010 from AngersZhuuuu/SPARK-33976.
Lead-authored-by: Angerszhuuuu <angers.zhu@gmail.com>
Co-authored-by: angerszhu <angers.zhu@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>