"Module tag names" rule refinement

[jbmoelker]

Summary

Proposed changes:

• Rename to "Tag module names".
• ToC as unordered list (like master readme).
• Split text into summary + why + how.
• Add (code) examples.
• Nuance app- namespace.

  Checklist

• [X] The changes only affect or contain one style guide rule or section.
• [X] The changes are in style guide format.
• [X] The new style guide section has an entry in the Table of Contents (only if changes introduce new section).
• [X] The changes can be merged into the target branch without conflicts.

…mespace.