Update manpage to match --help output
Update manpage to match --help output

Three command line options were added in late 2021
that never made their way into the manpage:

* f8ae334 introduced --no-ignore-parent;
* bf9e6fd introduced --strip-prefix
  (later renamed strip-cwd-prefix); and
* 17dd2a6 introduced --batch-size.

This commit updates the manpage content to reflect
the auto-generated output of `fd --help`.

sharkdp/fd,sharkdp/fd