Revert "openstack server create" to "nova boot" in nova docs

When this patch [1] was introduced, it didn't take into consideration,
the updated/changed/modified parameters when using OSC vs nova CLI, so not
every option can be used in "openstack server create" which was used in "nova boot"
and vice versa. This bug would track reverting some of these incorrect commands usage.

For example- "nova boot --block device <params1>" can be translated as
"openstack server create --block-device-mapping <params2>" where params1 and
params2 are formatted differently (hence needs more than a simple search/replace)

[1] https://review.opendev.org/#/c/404623/

Related-To: https://review.opendev.org/#/c/404623/
Change-Id: I8e400da9445101b9ff5240511c56105e26e16e4c
Closes-Bug: #1851425

doc/source/user/launch-instance-from-volume.rst

@@ -5,7 +5,7 @@ Launch an instance from a volume
 You can boot instances from a volume instead of an image.
 
 To complete these tasks, use these parameters on the
-:command:`openstack server create` command:
+:command:`nova boot` command:
 
 .. tabularcolumns:: |p{0.3\textwidth}|p{0.25\textwidth}|p{0.4\textwidth}|
 .. list-table::
@@ -13,7 +13,7 @@ To complete these tasks, use these parameters on the
    :widths: 30 15 30
 
    * - Task
-     - openstack server create parameter
+     - nova boot parameter
      - Information
    * - Boot an instance from an image and attach a non-bootable
        volume.
@@ -103,11 +103,11 @@ system.
 
    .. code-block:: console
 
-      $ openstack server create --flavor 2 --image 98901246-af91-43d8-b5e6-a4506aa8f369 \
+      $ nova boot --flavor 2 --image 98901246-af91-43d8-b5e6-a4506aa8f369 \
         --block-device source=volume,id=d620d971-b160-4c4e-8652-2513d74e2080,dest=volume,shutdown=preserve \
         myInstanceWithVolume
       +--------------------------------------+--------------------------------------------+
-      | Field                                | Value                                      |
+      | Property                             | Value                                      |
       +--------------------------------------+--------------------------------------------+
       | OS-DCF:diskConfig                    | MANUAL                                     |
       | OS-EXT-AZ:availability_zone          | nova                                       |
@@ -315,7 +315,7 @@ the volume to boot an instance.
    deleted when the instance is terminated.
 
    .. note:: The example here uses the ``--volume`` option for simplicity. The
-      ``--block-device`` option could also be used for more granular control
+      ``--block-device-mapping`` option could also be used for more granular control
       over the parameters. See the `openstack server create`_ documentation for
       details.