make `zoxide` fully `cd` compatible

Hey.

It would be nice if zoxide would be fully compaitble to cd (as defined by POSIX).

In particular, this would require supporting the -P, -L and -e options as well as -- to end option parsing (e.g. a mere cd -- is identicaly to cd, but z -- currently causes an "error").

AFAICS, already supports - as special directory name to go to OLDPWD.

Cheers, Chris.