docs(readme): add command-line options, cargo worskpace packages, installation instructions

[lrlna]

Description

This PR adds a few updates to the main README.md, inlcuding:

• a print out of current rover --help to outline available command-line options
• a list + appropriate description of each cargo workspaces packages
• a brief mention on downloading and installing the binary
• an update to rover-cli instead of apollo-cli

[EverlastingBugstopper]

some tiny nits here - thanks so much for taking the time to update the README as it is sorely out of date!

I've suggested renaming instances of rover to Rover, as we've made the decision to stylize as "Rover" instead of rover unless we're specifically in the context of running the CLI as a command.

[EverlastingBugstopper]

thanks!