Tick off box in Readme.

Readme.md

@@ -8,7 +8,7 @@ Currently it at least fully parses and compiles regexs for the complete Sublime
 
 - [x] Sketch out representation of a Sublime Text syntax
 - [x] Parse `.sublime-syntax` files into the representation.
-- [ ] Write an interpreter for the `.sublime-syntax` state machine that highlights an incoming iterator of file lines into an iterator of scope-annotated text.
+- [x] Write an interpreter for the `.sublime-syntax` state machine that highlights an incoming iterator of file lines into an iterator of scope-annotated text.
 - [ ] Parse TextMate/Sublime Text theme files
 - [ ] Highlight a scope-annotated iterator into a colour-annotated iterator for display.
 - [ ] Add C bindings so it can be used as a C library from other languages.