mgr/dashboard: fix nvmeof api documentation

mgr/dashboard: fix nvmeof api documentation

From Aviv:
POST /api/nvmeof/hosts - the description of the command it wrong IMO. It is not about creating a host. It is about allowing a host X to access subsystem Y.
GET /api/nvmeof/hosts/{subsystem_nqn} - also the description is not accurate. The command lists all hosts that are allowed to access this subsystem.
DELETE /api/nvmeof/hosts/{subsystem_nqn}/{host_nqn} - again the description should be changed as above.
POST /api/nvmeof/namespace - bad formatting of the description
GET /api/nvmeof/subsystem - the description is wrong, should say - "List all NVMeoF subsystems". And it shouldn't get any param.
POST /api/nvmeof/subsystem - few issues here. The serial_number, and max_namespaces are optional (we need to mention that). Also it is missing the --enable-ha argument that is also optional.
Some commands are missing: log_level, connection.i

Fixes: https://tracker.ceph.com/issues/64714
Signed-off-by: Nizamudeen A <nia@redhat.com>