Start init script with initializing submodules

I am setting up a new laptop and ran into a hiccup because my dotfiles
submodules were not initialized. This ensures that this critical step
happens.
Add jsxhint to Syntastic checkers

I'm developing with JSX a lot more these days, and it is nice to have
Syntastic tell me about issues in these files as I go along.
Add some words to custom dictionary

As I've been writing things, I've come across a few words that were not
in the default dictionary that should be.