fix(docs) Add Esperanto support to README.md

[RobinvanderVliet]

Support for Esperanto was added in #2285, but this is not yet fully documented in README.md. This pull request fixes that.

Checklist

• PR contains only changes related; no stray files, etc.
• README updated (where applicable)
• Tests written (where applicable)
• References provided in PR (where applicable)

[WikiRik]

@profnandaa if it's still on time, this might be a good final addition to the release

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (83d6ffd) to head (652ae6d).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##            master     #2394   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          108       108           
  Lines         2482      2482           
  Branches       627       627           
=========================================
  Hits          2482      2482           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.