Add an entry in the sibling file in the appropriate category section, containing a DESCRIPTION of the goal of the pattern (i.e. what it enables you to implement), accompanied by a pointer to a markdown DOCUMENT in the directory.

IMPORTANT - The DESCRIPTION should be clear enough that future YOU can effectively use it to MATCH design problems you may encounter in future.

In that DOCUMENT, describe the idea of the implementation along with code examples. Follow the format of existing pattern files (Problem, Solution, Complete Code Example, Key Points, When to Use).