DOC: Simplify contributing intro
* Reduced some preamble
* Updated some links
* Use `code-block:: shell` where appropriate
nice! @noatamir fancy taking a look? interested in adding yourself to https://github.com/pandas-dev/pandas/blob/main/.github/CODEOWNERS for `doc/source/development` (and anything else)? Hmm, @mroeschke the doc build is failing and it looks like an extensive change. Any chance you have screenshots from a local build or can you please fix the build issue?  /preview Website preview of this PR available at: https://pandas.pydata.org/preview/54220/ @noatamir was able to fix the issue and generate the preview This is great! I made a few small suggestions.  Thanks all the suggestions looked great