DOCTEST: Add a second file in order to test impact

[karenzone]

Testing to see if we can safely add a second file to the /docs/ directory without disrupting normal docgen processing.

Goal: Find the best approach for handling aliased plugins.

Test Plan:

• Introduce test file (do not include in changelog).
• Bump version and publish gem.
• Generate plugin docs to be sure that extra file doesn't cause problems. Look for any unexpected consequences.
• Delete testfile.

@Andsel Perhaps we can work together to run this test when you finalize #169. This could be relevant to other project we're working on together.