Add support for hljs aliases for code hints

Contribute Feature
9

I don’t think the auto highlighting is working then. Even on this site, observe the following

No language name:

let x = 10;

function root(n) {
  return Math.sqrt(n);
}

console.log(root(x));

javascript as language name:

let x = 10;

function root(n) {
  return Math.sqrt(n);
}

console.log(root(x));

There is a difference in appearance, indicating a different set of rules is being applied (even though both are identical JavaScript). And it’s not just these two language that would benefit from allowing synonyms; there are quite a few that offer alternative naming.