Document all "when clauses" for the extension

[macintacos]

It took a while to figure out that I had to use vim.mode == 'VisualLine' instead of vim.mode == 'Visual Line' or vim.mode == 'Visual-Line' etc. because I couldn't find them in the README. Can we have all of the various "modes" documented in the README? Thanks!

[stevenguh]

I agree, it does require some source code digging. I think here are all the modes.

Vim/src/mode/mode.ts

Lines 8 to 20 in 91ca71f

	Normal,
	Insert,
	Visual,
	VisualBlock,
	VisualLine,
	SearchInProgressMode,
	CommandlineInProgress,
	Replace,
	EasyMotionMode,
	EasyMotionInputMode,
	SurroundInputMode,
	OperatorPendingMode, // Pseudo-Mode, used only when remapping. DON'T SET TO THIS MODE
	Disabled,