DOC: update pandas cheat sheet with a third page (fixes #40680)
- [x] closes #40680
- [x] added 3rd page to the cheat sheet including more details on plotting, frequently used options, input/output formats and more.
- [x] added `.info()`, `.memory_usage()`, and `.dtypes()` to 'Summarize Data' on page 2 and rearranged the page to fill the gap left by the old plotting section.

Thanks for the feedback, this is my first time contributing to anything so thanks for being so constructive. I think I've addressed all the issues raised. Changes have been pushed so let me know if anything else needs updating! Thanks again, I've updated the powerpoint according to the feedback, made the pdf version, and editted the README.md file as well. @Shoestring42 looking forward to having you address my last comment here:  https://github.com/pandas-dev/pandas/pull/61378#pullrequestreview-2809938830
 changes have been pushed. Sorry it took so long, exam period has just started at uni so i've been busy revising. Thanks for your patience.