readme enhancements

[wenxi-zeng]

• integrate codecov
• update compatibility notes
• add badges

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (main@d3a1a99). Click here to learn what that means.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main      #61   +/-   ##
=======================================
  Coverage        ?   81.08%           
  Complexity      ?      491           
=======================================
  Files           ?       65           
  Lines           ?     6869           
  Branches        ?      635           
=======================================
  Hits            ?     5570           
  Misses          ?      795           
  Partials        ?      504           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update d3a1a99...73bff79. Read the comment docs.

[prayansh]

❤️

[wenxi-zeng]

got approval from security. as long as we are not using codecov github action v1 and bash uploader, we are good.