Adding in further NG-Doc comments for Documentation

Hello @nul800sebastiaan I have started a small initial Pull Request for improving & adding in missing NG-Doc comments to the JS source files for the Belle Documentation files.

Is it possible that @perploug & or @Shandem can review this small set of changes to begin with before I invest time to try comment & document more stuff that is missing currently.

Cheers,
Warren :smile: