DOC: add backticks to docstrings
- [ ] Issue DOC: Inconsistent use of code-style formatting (backticks) in docstrings #53674
- [ ] Issue originally referenced only read_csv and read_excel but open to 
all docstrings to update this formatting for consistency

This PR doesn't address all backsticks needed in pandas/io/xml.py but want to get the ball rolling to see if I'm headed in the right direction. 
Thanks @wcgonzal  Thank you, will  continue working on this. 