Feature update tutorial instructions

[jprestop]

Expected Differences

• Do these changes introduce new tools, command line arguments, or configuration file options? [No]
  
  If yes, please describe:
  

Pull Request Testing

• Describe testing already performed for these changes:
  
  Reviewed the changes in RTD (https://fasteddy-model.readthedocs.io/en/feature_update_tutorial_instructions/Tutorials/cases)

• Recommend testing for the reviewer(s) to perform, including the location of input datasets, and any additional instructions:
  
  @jsauer-NCAR Please review the changes via the Files Changed tab and/or through RTD (https://fasteddy-model.readthedocs.io/en/feature_update_tutorial_instructions/Tutorials/cases). Please note that I only ran through the SBL dispersion case, but it looks like the instructions would be the same for the CBL case as well. Please let me know if you'd like me to run through the CBL case as well.

• Do these changes include sufficient documentation updates, ensuring that no errors or warnings exist in the build of the documentation? [Yes]

• Do these changes include sufficient testing updates? [Yes]

• Will this PR result in changes to the test suite? [No]
  
  If yes, describe the new output and/or changes to the existing output:
  

• Please complete this pull request review by [at your convenience].
  

Pull Request Checklist

• Complete the PR definition above.
• Ensure the PR title matches the feature or bugfix branch name.
• Select: Reviewer(s)
• [No corresponding issue] After submitting the PR, select the ⚙️ icon in the Development section of the right hand sidebar. Search for the issue that this PR will close and select it, if it is not already selected.
• After the PR is approved, merge your changes. If permissions do not allow this, request that the reviewer do the merge.
• Close the linked issue and delete your feature or bugfix branch from GitHub.