[DOCS] Note readthedocs bug in README

[dyfrgi]

Add a warning about #3059 to the docs link.

Changes

This does not fix #3059, but it adds a warning so that anyone following this link to the docs will know that they are out of date.

[linux-foundation-easycla]

• ❌ - login: @dyfrgi / name: Michael Leuchtenburg . The commit (897b94d) is not authorized under a signed CLA. Please click here to be authorized. For further assistance with EasyCLA, please submit a support request ticket.

[dyfrgi]

I'm working on the CLA with my employer.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.05%. Comparing base (f2bc1e7) to head (897b94d).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4054      +/-   ##
==========================================
+ Coverage   82.04%   82.05%   +0.02%     
==========================================
  Files         385      385              
  Lines       15895    15895              
==========================================
+ Hits        13039    13041       +2     
+ Misses       2856     2854       -2     

see 1 file with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[marcalff]

LGTM.

To be revisited later once opentelemetry-cpp resolves how to publish up to date documentation.