Update README.md

[ahcorde]

🦟 Documentation fix

Fixes gazebosim/gazebo_test_cases#105

Summary

Fixed link and improve visualization

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[codecov]

Codecov Report

Merging #381 (8f70a68) into gz-msgs10 (b6e42df) will not change coverage.
The diff coverage is n/a.

❗ Current head 8f70a68 differs from pull request most recent head 35b4cc6. Consider uploading reports for the commit 35b4cc6 to get more accurate results

@@            Coverage Diff             @@
##           gz-msgs10     #381   +/-   ##
==========================================
  Coverage      97.26%   97.26%           
==========================================
  Files             27       27           
  Lines           1169     1169           
==========================================
  Hits            1137     1137           
  Misses            32       32