Update after.md document for enums exercise
Update after.md document for enums exercise

* Update after.md document for enums exercise

* Update languages/exercises/concept/enums/.docs/after.md

Co-Authored-By: Jeremy Walker <748be3168291910db6bd9ae2b7d028582a439c01@gmail.com>

Co-authored-by: Jeremy Walker <748be3168291910db6bd9ae2b7d028582a439c01@gmail.com>

exercism/xcsharp,exercism/xcsharp