README: Fix list rendering
README: Fix list rendering

The list was previously rendered with "1. ... / 1. ... / 1. ..." instead of "1. ... / 2. ... / 3. ...". I've also removed the `$` prefixes to make it easier to copy-paste the commands.
glidernet/ogn-python,Meisterschueler/ogn-python,kerel-fs/ogn-python,Meisterschueler/ogn-python,glidernet/ogn-python,glidernet/ogn-python,Meisterschueler/ogn-python,glidernet/ogn-python,Meisterschueler/ogn-python