README.rst: formatting error corrected (fixup)

https://github.com/drothlis/stb-tester/pull/9#commitcomment-3122738
README.rst: Exaple URIs for the lirc remote (fixup)

The BNF notation
  lirc:([<lircd_socket>]|[<hostname>:]<port>):<remote_control_name>
is a bit complicated; it should help the users of stbt if they find
a few usage examples.