Normally I would let `eslint --fix` do this for me, but there's a bug
that causes:
const x = function ()
{
// ...
};
to become:
const x = ()
=> {
// ...
};
which ESLint thinks is a syntax error. (It probably is; I don't know
enough about the automatic semicolon insertion rules to be confident.)
It's just synctactic sugar, but it is always better than executing string
concatenations in one's mind.
Do not do this with files in src/static, because we want to keep IE 11
compatibility.
