This patch adds a --version and a --help flag

--version
radicle-httpd pre-release (b68ea537)

--help
Usage

   radicle-httpd [<option>...]

Options

    --listen       <address>         Address to listen on (default: 0.0.0.0:8080)
    --alias, -a    <alias> <rid>     Provide alias and RID pairs to shorten git clone commands for repositories,
                                     e.g. heartwood and rad:z3gqcJUoA1n9HaHKufZs5FCSGazv5 to produce https://seed.radicle.xyz/heartwood.git
    --cache        <number>          Max amount of items in cache for /tree endpoints (default: 100)
    --version, -v                    Print program version
    --help, -h                       Print help