linting + syntax checking

[missinglink]

There is currently no linting or syntax checking enabled for this repo, which means that there are variable levels of code quality throughout the codebase.

There are a few options to set it up, all of which are fairly painful tasks:

• configure our standard jshint + precommit-hook setup
• configure something more modern like eslint
• use standardjs which also uses the eslint rules (AFAIK)

I opted for the third option for a couple reasons:

• standard --fix will automatically reformat a bunch of the code, saving time and preventing error
• while I'm not 100% in love with all the decisions, I like standardjs because it means everyone writes the same style.

I started doing the refactor and had to give up after ~30mins because it's such a horrible task, I'm going to leave this PR open to be finished another day.

I'd also be happy if this PR were superseded by another quicker method of getting linting + syntax checking enabled for this repo.

To view the remaining errors (~300):

git commit