DOC: Code style documentation
- [x] ref [(comment)](https://github.com/pandas-dev/pandas/pull/29963#discussion_r353760238)
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

This still needs a lot more work.
I will appreciate any advice/idea/fix.
Thanks @MomIsBestFriend 

@WillAyd can you have a look and see if your comments were addressed please? @MomIsBestFriend can you have a look at the CI please? Seems some things are failing. ```
 Linting code-blocks in .rst documentation
##[error]doc/source/development/contributing_code_guide.rst:59:10:F821:undefined name 'new_function_name'
##[error]doc/source/development/contributing_code_guide.rst:59:21:F821:undefined name 'old_function_name'
##[error]doc/source/development/contributing_code_guide.rst:69:10:F821:undefined name 'new_function_name'
##[error]doc/source/development/contributing_code_guide.rst:69:21:F821:undefined name 'old_function_name'
``` I have no idea how to solve it

https://github.com/pandas-dev/pandas/commit/02c0ab52d13dc00623bdf58a08bc51bc5818a2a1/checks?check_suite_id=379658620#step:6:2335 > I have no idea how to solve it

You can add the new page to this index. So, it's visible, and the error should also disappear. Sorry, I see I forgot to copy the link. Another option is to add the document to this index, instead of creating a new one: https://github.com/pandas-dev/pandas/blob/master/doc/source/development/index.rst > Sorry, I see I forgot to copy the link. Another option is to add the document to this index, instead of creating a new one: https://github.com/pandas-dev/pandas/blob/master/doc/source/development/index.rst

This is your preferred way? Up to you, but I think it'd make the page more visible if it's in that index.  > Up to you, but I think it'd make the page more visible if it's in that index.

Since you suggested it, I will go with that.

Do I just put ```contributing_code_guide``` under ```developer``` for example?

(and remove the ```doctree``` in ```contributing.rst```?) Yep, just have your page as one more item in the list, not sure what's the best position, up to you.

You can probably leave a regular link in contributing, I guess you added an index because of the error I'm considering changing the file name to ```style``` or something like that, to make it one word, instead of three. > I guess you added an index because of the error

Correct. I hope I did it correct. > I'm considering changing the file name to `style` or something like that, to make it one word, instead of three.

I think style may be a bit ambiguous with other parts of the docs. But renaming to `code_style` sounds like a great idea. @WillAyd can you have a look please? This should be ready Thanks @momisbestfriend