add login: and url:

[thimble]

qtpass and rofi supporting the field starting with "login:" and "url:" to store the corresponding url of an entry. Can you support this and add a hotkey to copy the login/url value to the clipboard?

[Kwpolska]

I implemented copying arbitrary fields in #18, which went out as v0.2.0. Is this enough? Or perhaps you would be better satisfied with special one-button handling for those? (The current flow requires displaying first, then picking a field)