feat: add llms.txt and llms-full.txt

[5ZYSZ3K]

Add llms.txt and llms-full.txt to help llms learn the project

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.65%. Comparing base (b829513) to head (e6fe5ea).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #42   +/-   ##
=======================================
  Coverage   98.65%   98.65%           
=======================================
  Files         140      140           
  Lines        2085     2085           
  Branches      632      635    +3     
=======================================
  Hits         2057     2057           
  Misses         27       27           
  Partials        1        1           

Flag	Coverage Δ
css-processor	100.00% <ø> (ø)
render	97.85% <ø> (ø)
transient-render-engine	98.95% <ø> (ø)

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[jsamr]

How do we make sure this doesn't get out of sync? Isn't it new maintenance surface? I'm also not familiar with llms.txt, is this part of a standard?