Initial version

Written for
https://github.com/renatoathaydes/CeylonFX/commit/c0bbce02b4de0db8c13cc96e0078b70a7f8f0e6b.
Can’t even handle multi-line comments.
README.md: Usage
Correctly parse multi-line comments
README.md: Replace intro with usage, new usage

The previous "usage" didn’t really describe the usage at all.
README.md: Add TODO section