Update stability info in documentation

[mikenerone]

This PR updates the README to better reflect Trio’s current maturity. The previous wording hadn’t been updated since it was originally written eight years ago and no longer accurately represented Trio’s suitability for production use.

No functional changes—just a documentation update for clarity.

[CoolCat467]

Looks solid to me

[A5rocks]

Could you update the docs? They have this paragraph too.

[mikenerone]

@A5rocks

Could you update the docs? They have this paragraph too.

Good call, updated several places in the docs.

[agronholm]

How about also updating this line?

[mikenerone]

@agronholm

How about also updating this line?

Done!

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00000%. Comparing base (4df83b4) to head (5ac6aeb).
Report is 149 commits behind head on main.

Additional details and impacted files

@@               Coverage Diff               @@
##                 main        #3216   +/-   ##
===============================================
  Coverage   100.00000%   100.00000%           
===============================================
  Files             124          124           
  Lines           18770        18770           
  Branches         1269         1269           
===============================================
  Hits            18770        18770           

Files with missing lines	Coverage Δ
src/trio/_deprecate.py	100.00000% <ø> (ø)

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[A5rocks]

Thanks for working through the wording. I'd like @njsmith to weigh in before we merge this.

[Zac-HD]

lgtm - Anthropic has been using Trio in production for years now, and we're very happy with it 😁

[njsmith]

lgtm