add a readme

[eepykate]

it should

• tell you how to build
• tell you how to set up a server
• tell you how to connect to a server
• tell you the basic controls (ex: delete for clear)
• say the window needs to be of a specific size or it won't properly and the chat won't render (Limitations section)

[RustemB]

WiP

[elkowar]

I'm currently reworking the Command line interface, so we should probably wait until that is at least semi-finalized

[eepykate]

@elkowar Also I'd recommend adding something saying delete no work on st and the fix (either use another term, or make st use ^[[3~ for the delete escape seq instead of ^[[P)

[Swexti]

i made a readme since no one did it. thank me later