Add Functions section to Javascript snippets page?

[mateusmlo]

The Javascript snippets page currently have separate sections for subjects which fall under a same category: Functions. The subjects are [Useful Functions] and [Closures] - those could be subsections of [Functions] instead. If we were to add more info about functions in general (as I'd like to do), this could help keep things organized.

[rickwest]

Sure, that makes total sense @mateusmlo, happy for the pages to be reorganised in this way :-)