docs(contributing): add Contributing TL;DR page

[bearomorphism]

Description

I believe the new page makes it easier for developers to understand how to contribute effectively.

Checklist

• I have read the contributing guidelines

Documentation Changes

• Run poetry doc locally to ensure the documentation pages renders correctly
  • Check if there are any broken links in the documentation

When running poetry doc, any broken internal documentation links will be reported in the console output like this:

INFO    -  Doc file 'config.md' contains a link 'commands/bump.md#-post_bump_hooks', but the doc 'commands/bump.md' does not contain an anchor '#-post_bump_hooks'.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.62%. Comparing base (120d514) to head (f274846).
Report is 660 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1484      +/-   ##
==========================================
+ Coverage   97.33%   97.62%   +0.28%     
==========================================
  Files          42       57      +15     
  Lines        2104     2653     +549     
==========================================
+ Hits         2048     2590     +542     
- Misses         56       63       +7     

Flag	Coverage Δ
unittests	97.62% <ø> (+0.28%)	⬆️

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[Lee-W]

I love it! but would like to keep it for a few days so that others can check whether this new page works good 🙂