chore(docs): add demo and usage

Author: 0x77dev

README.md

@@ -3,14 +3,19 @@ peerchat
 
 Peer-to-peer terminal chat based on [DStack](https://github.com/dstack-js/dstack)
 
+![Demo](docs/demo.svg)
+
+_Recording looks ugly, but in terminal it seems to be fine_
+
 [![oclif](https://img.shields.io/badge/cli-oclif-brightgreen.svg)](https://oclif.io)
 [![Version](https://img.shields.io/npm/v/peerchat.svg)](https://npmjs.org/package/peerchat)
 [![Downloads/week](https://img.shields.io/npm/dw/peerchat.svg)](https://npmjs.org/package/peerchat)
 [![License](https://img.shields.io/npm/l/peerchat.svg)](https://github.com/dstack-js/chat/blob/master/package.json)
 
 <!-- toc -->
-* [Usage](#usage)
-* [Commands](#commands)
+- [peerchat](#peerchat)
+- [Usage](#usage)
+- [Commands](#commands)
 <!-- tocstop -->
 # Usage
 <!-- usage -->
@@ -22,7 +27,19 @@ $ peerchat (-v|--version|version)
 peerchat/0.0.1 darwin-x64 node-v16.13.1
 $ peerchat --help [COMMAND]
 USAGE
-  $ peerchat COMMAND
+  $ peerchat [ROOM] [NICKNAME]
+
+ARGUMENTS
+  ROOM      [default: dstack] chat room
+  NICKNAME  your nickname
+
+OPTIONS
+  -v, --version  show CLI version
+
+EXAMPLES
+  $ peerchat
+  $ peerchat ROOM NICKNAME
+  $ peerchat dstack myCoolNickname
 ...
 ```
 <!-- usagestop -->