docs(README.md): fix typo and make documentation conspicuous
docs(README.md): fix typo and make documentation conspicuous

sru/clap-rs,cstorey/clap-rs,cstorey/clap-rs,clap-rs/clap,clap-rs/clap,kbknapp/clap-rs,clap-rs/clap,sru/clap-rs,sru/clap-rs,kbknapp/clap-rs,cstorey/clap-rs