Support VIM j,k,h,l fast move cursor

[JerryZheng89]

When i use vim in webssh, long press (j,k,h,l) keys button, it cannot move fast toward down, up, left, and right, and the cursor don't move.

[isontheline]

Hello @JerryZheng89 👋

An issue is already opened here : #976

Yet WebSSH lacks of key repeat.

I'll try to implement this feature