added sql grammar

I suppose we could pull out the "pure" mustache into its own grammar, but let's worry about that for the next one.
Mind putting the `scopeName` at the very top followed by the `name`. I know other grammars don't do that, that is because they were auto-generated but going forward I've been trying to move the `scopeName, `name, and `fileTypes` to the top for readability whenever I make a change.