Vim mode

[tomlin7]

Feature

As many code editors now come with built-in Vim mode, it would be a great enhancement to add this feature to Biscuit.
This issue will address only the basic steps of implementing Vim mode.

🚧 As this is a large feature, individual issues/pr shall be opened for individual parts of this feature.

Suggestions needed on following

We aim to create something bit different from existing vim mode plugins of editors

• where to show the current mode? status bar, title bar, or somewhere else?
• where to show the command line?

TODO

• toggle vim mode via settings, keyboard shortcut, welcome page, or command palette
• normal, insert, visual, and command modes indicator

Normal mode

• h, j, k, l for navigation
• beginning of the file: gg, end of file G
• dd (delete line), yy (yank line), p (paste)
• u (undo), ctrl-r (redo)
• x (delete), dw (delete from cursor to word end), diw (delete word under cursor), cw (cut from cursor to word end), ciw (cut word under cursor)

Visual mode

• select text with v or mouse
• line selection with V

Insert mode

• i (insert), I (insert at line start), a (insert after cursor), A (insert at line end), o (insert in new line), O (insert in new line above)
• esc to go back to normal mode.

Command Mode (:)

• :w (save), :q (quit), :wq (save and quit)
• goto line :64