examples: add examples/, fix README

examples/runcmd.v

@@ -0,0 +1,27 @@
+module main
+
+import time
+import qga
+
+fn main() {
+	args := arguments()[1..]
+	eprintln('Run this example as: `v -d trace_guest_agent run runcmd.v SOCKET_PATH COMMAND`')
+	eprintln('')
+	mut ga := qga.Client.new(args[0] or { panic('socket path is not provided') })!
+	eprintln('Ping guest agent...')
+	ga.ping() or { panic('ping failed...') }
+	eprintln('Ping successfull!')
+	eprintln('Run command!')
+	pid := ga.exec('/bin/sh',
+		args:           ['-c', args[1] or { panic('COMMAND is not provided') }]
+		capture_output: true
+	)!
+	for {
+		status := ga.exec_status(pid)!
+		time.sleep(500 * time.millisecond)
+		if status.exited {
+			println(status)
+			break
+		}
+	}
+}