Support Ctrl+A, Ctrl+E and Ctrl+W in read_line

[jeremie-stripe]

Describe the problem

A potential suggestion/feeling check before I go ahead and try to contribute. We have a user of our CLI tool (which uses shiny TTY::Prompt) that was asking to be able to use the classic Ctrl combination for navigation and editing of a prompt.ask (Ctrl+A to go at the start of a line, Ctrl+E for end and Ctrl+W to erase the prefilled value).

How would the new feature work?

My instinct would be that we just need to add those 3 cases I mention in

tty-reader/lib/tty/reader.rb

Lines 338 to 339 in ac92571

	elsif key_name.to_s =~ /ctrl_/
	# skip

to mirror the currently handling that's done with :home, :end and add one for erasing.

Drawbacks

Not sure if handling this would cause ripple effects through some other systems that expect it to be available.

[coezbek]

I guess the question is if this is an desired capability for tty-reader considering the text from the Readme: "The tty-reader is not compatible with the GNU Readline and doesn't aim to be. "