Add footnote detail hotkey

[Comprehensive-Jason]

Some users (https://github.com/MichaBrugger/obsidian-footnotes/issues/21#issuecomment-1821375264) prefer adding footnote details first, then referencing them later using the Autosuggest feature.

Add a footnote detail hotkey that does the following based on press number:

Press 1: Adds an empty footnote detail at the end of the note. Places cursor inside brackets so user can write the marker name. Press 2: Places cursor after colon so user can write footnote detail content. Press 3: Repeat of Press 1