🌱🥳: Fixes to tutorials

[chapulina]

🦟 Bug fix

• gz-math: Vector example garden-tutorial-party#245

Summary

A few fixes to the vector tutorial, while testing binaries on Ubuntu Focal, and went ahead and fixed other places too

• Clone correct branch
• I initially didn't have the Ruby bindings installed, so I think it's helpful to explicitly tell how to install them

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 #492 (07b736f) into gz-math7 (0f16476) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           gz-math7     #492   +/-   ##
=========================================
  Coverage     99.70%   99.70%           
=========================================
  Files            77       77           
  Lines          7007     7007           
=========================================
  Hits           6986     6986           
  Misses           21       21           

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.