Add snippet section link for turning off automatic updates

[jeffpaul]

Description of the Change

In reviewing https://10up.github.io/distributor/tutorial-snippets.html#modify-custom-meta-data I noticed there was one more section that's not included in the TOC at the top of the page, so this PR attempts to fix that and add in that section link.

This pull request adds a new documentation entry to the docs/snippets.md file, updating the list of available snippet topics.

• Documentation update:
  • Added a link to a new section on how to turn off automatic updates for distributed content in the snippet topics list.

How to test the Change

Changelog Entry

n/a

Credits

Props @jeffpaul.

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added Critical Flows, Test Cases, and/or End-to-End Tests to cover my change.
• All new and existing tests pass.