Update and simplify the lima documentation. Try to reference and direct
users more to upstream documentation as generally upstream processes can
be followed without special requirements for lima.

Try to remove old information and not maintain information that gets out
of date quickly. Point to the issue tracker rather than maintain a
duplicated list of issues and status here.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Reviewed-by: Qiang Yu <yuq825@gmail.com>