Add comment/uncomment bindings

This might be more broadly addressed with custom mappings/bindings, but adding comment/uncomment bindings would be super useful. Somehing along the lines of tpope’s commentary which uses gc as the binding for commenting.

[llinfeng]

@CrashLaker You shall find a relevant discussion in #17.

[llinfeng]

Update on using Ctrl + / for commenting

As mentioned by DreamFlasher’s comment in this stack overflow post, the slash symbol (/) should be interpreted as the slash symbol from the Numpad!!!

On my Windows machine, I added the following mapping to tune the normal Ctrl + / key-press into the real thing: Ctrl + Numpad-Slash.

; I used a program called AutoHotKey
; Section that declares the `ahk_group JupyterLab`: this shall capture all cases where I may be using Jupyter
SetTitleMatchMode, 2
GroupAdd , JupyterLab       , JupyterLab - Mozilla Firefox 
GroupAdd , JupyterLab       , JupyterLab - Vimperator
GroupAdd , JupyterLab       , JupyterLab - Google Chrome 
GroupAdd , JupyterLab       , JupyterLab ahk_exe chrome.exe
return


; The simple mapping, along with other things that emulate Vim's fundamental actions.
#IfWinActive ahk_group JupyterLab
    ^/:: send ^{NumpadDiv}
    ^w::Send ^+{Left}{BS}
    ^h::Send {BS}
return