Minor updates to the thermal camera tutorial

[iche033]

🦟 Bug fix

gazebosim/gazebo_test_cases#187

Summary

Tweaks to links and instructions

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 #379 (40bd31c) into gz-sensors8 (cb20312) will not change coverage.
The diff coverage is n/a.

❗ Current head 40bd31c differs from pull request most recent head 74e2d9e. Consider uploading reports for the commit 74e2d9e to get more accurate results

@@             Coverage Diff              @@
##           gz-sensors8     #379   +/-   ##
============================================
  Coverage        72.76%   72.76%           
============================================
  Files               36       36           
  Lines             4968     4968           
============================================
  Hits              3615     3615           
  Misses            1353     1353