Avoid parsing lyx files as md files
Avoid parsing lyx files as md files

Summary:
Should have been part of d51ce3e47271ba1eba88f1fa1d64f9a3374b7c4f
Ref T368

Test Plan: go test

Reviewers: dd

Reviewed By: dd

Maniphest Tasks: T368

Differential Revision: https://p.daedalean.ai/D313

daedaleanai/reqtraq