Fix doc prompts (#1074)

* add $ prompt

* add space

Author: akira6592

docs/docsite/rst/network/getting_started/first_inventory.rst

@@ -412,7 +412,7 @@ To see the original value, you can use the debug module. Please note if your YAM
 
 .. code-block:: console
 
-   cat vyos.yml | grep -v ansible_connection >> vyos_no_connection.yml
+   $ cat vyos.yml | grep -v ansible_connection >> vyos_no_connection.yml
 
    ansible localhost -m debug -a var="ansible_password" -e "@vyos_no_connection.yml" --ask-vault-pass
    Vault password:

docs/docsite/rst/network/user_guide/network_debug_troubleshooting.rst

@@ -578,7 +578,7 @@ Example: Handle single login menu prompts with host variables
 
 .. code-block:: console
 
-    $cat host_vars/<hostname>.yaml
+    $ cat host_vars/<hostname>.yaml
     ---
     ansible_terminal_initial_prompt:
       - "Connect to a host"
@@ -589,7 +589,7 @@ Example: Handle remote host multiple login menu prompts with host variables
 
 .. code-block:: console
 
-    $cat host_vars/<inventory-hostname>.yaml
+    $ cat host_vars/<inventory-hostname>.yaml
     ---
     ansible_terminal_initial_prompt:
       - "Press any key to enter main menu"

docs/docsite/rst/network/user_guide/validate.rst

@@ -91,7 +91,7 @@ The criteria for ``jsonschema`` in this example is as follows:
 
 .. code-block:: text
 
-  $cat criteria/nxos_show_interface_admin_criteria.json
+  $ cat criteria/nxos_show_interface_admin_criteria.json
   {
         "type" : "object",
         "patternProperties": {