Allow any protocols for links

[cmrd-senya]

This issue is similar to #180 which was solved before.

I think this should be made even more flexible. Why restrict link types only to three options currently? There are many other types of links that might be desirable. For example bitcoin://, ftp://, magnet://, tg:// or many others which we can't think of currently, but which a user may want to enter. I think we should allow any text at all, or make configurable regexp, or just regexp colon like \w+:\.+, or something else, but we shouldn't make assumptions on protocols which we allow.