Automatic insertion of `///`/`*`/`+` on enter.

[HuskyNator]

As a small enhancement request, The insertion of ////*/+ in respective comment blocks on pressing enter would make comments much less tedious.

This is comparable to the same feature in cpp: https://github.com/Microsoft/vscode-cpptools/issues/579

[WebFreak001]

note: probably either won't add /// or make it so double enter removes an empty line again