[dox] Fixing the lexical rule for BinaryInteger

[Andre Artus]

-- SNIP --

> I wrote that grammar as part of my work on DCD and DScanner. My 
> lexer, parser, and AST library need some more testing. Please 
> download DScanner and run it with either the --ast or 
> --syntaxCheck options. If you find issues, please report them 
> on Github.

I forked just under an hour ago, am I on old bits?
I have fixed all but one of the build issues, I would like to fix 
the last one before I commit as I don't like to leave my repo's 
in a broken state.

I'll continue the discussion on GitHub.