DOC: Get rid of question marks in getting started tutorials
- [x] closes #48227 (Replace xxxx with the Github issue number)
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

@MarcoGorelli I adjusted PR so that it remains as is [aka `How do I create plots?` in the code]. 

However, I noticed that in the docs for some reason the [plots](https://pandas.pydata.org/docs/getting_started/intro_tutorials/04_plotting.html#) heading shows `How to` with a question mark and when I added the previous change with `How to` without question mark building the docs got rid of the question mark on that page.

Not sure how the code show `How do I` when the docs show the heading `How to`.... > Not sure how the code show `How do I` when the docs show the heading `How to`....

you probably just need to do `python make.py clean` first @MarcoGorelli I have updated the dashes to be the length of the alter titles. Sorry about that. Thanks @samrao1997 