DOC: Fix GL01 docstring errors in some functions
- [x] fixes #36874
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

There are some GL01 pandas docstring errors in `shared_docs.py`.
```
GL01
Docstring text (summary) should start in the line immediately after the opening quotes (not in the same line, or leaving a blank line in between.
```