doc: add doc for tty writes ( readline.js / REPL )

[shobhitchittora]

The readline interface is missing the keybindings docs for possible input to tty. Attaching a list of possible bindings to be added to the doc.

KeyBindings	Description
ctrl+shift+backspace	delete line left
ctrl+shift+delete	delete line right
ctrl+c	emits SIGINT
ctrl+h	delete left
ctrl+d	delete right or EOF
ctrl+u	delete from current to line start
ctrl+k	delete from current to end of line
ctrl+a	goto start of line
ctrl+e	goto to end of line
ctrl+b	back one character
ctrl+f	forward one character
ctrl+l	clear screen
ctrl+n	next history item
ctrl+p	prev history item
ctrl+z	(need clarification)
ctrl+w or ctrl+backspace	delete backwards to a word boundary
ctrl+delete	delete forward to a word boundary
ctrl+left	word left
ctrl+right	word right
meta+b	word left
meta+f	word right
meta+d or meta+delete	delete word right
meta+backspace	delete word left

[shobhitchittora]

@BridgeAR can you suggest the correct place to add these bindings. Are these to be added to REPL doc or readline doc. Also for now I just took the Description from the comments in the code, probably a better description is in order. Can you add the concerned group to help with this?

Thanks. 😇