New feature (compare)

[ezequias]

Hi there

Firstly I would like to tank you for this useful tool and than I would like to suggest to enable a compare feature in a way we could see differences from one file to another.

This would be useful for people who likes to make translations like me and see the text changing during translation (it could be shown as a default sublime 3 text selection).

Thanks in advance.

Sincerely
Ezequias Rocha

[zzjin]

SInce I transfer to use vscode, which have a build in compare view.
This repo need new maintainer, and also contributions are wlecome.