Enhance json structure

I think it would be good to add another field to the JSON.

Simple things like a “description” field below the name field to describe the source, like the description here: https://library.hydra.wiki/library This short description could already be used for library.hydra, and it could also be seen in the launcher in the sources. For each download, a “password” field to enter the archive password if there is one, which could be displayed during download and used during auto-extraction. I saw that during download there was an auto-extraction option and that it worked even for online-fix when there is a password. I'm not sure how it works, whether you hardcoded the password for this source or something like that. A “Note” field would also be nice. We could write installation instructions, for example, or something else.

Obviously, these would be optional fields in order to be compatible with the current sources.