doc/dev: refresh vstart.sh options in dev_cluster_deployment

Bring doc/dev/dev_cluster_deployment.rst back in line with the current
src/vstart.sh:

* drop the removed -K/--kstore objectstore backend
* drop -N/--not-new, which was dropped in 8dd2e418; reusing the existing
  cluster config is simply the default when -n is not given
* correct the --rgw_frontend default from civetweb to beast
* note that -b/--bluestore is the default objectstore backend
* update the example and add a note that a fresh build needs -n on the
  first run, while later runs can omit it
* note that the option list is not exhaustive and point at src/vstart.sh

Fixes: https://tracker.ceph.com/issues/57272
Signed-off-by: Kefu Chai <k.chai@proxmox.com>