Avoid having module documentation links to itself (#21329)

* Avoid having module documentation links to itself

A lot of modules use M(own_module) in their documentation causing a link
in the documentation to itself.

* Make note more clear now

lib/ansible/modules/notification/grove.py

@@ -26,7 +26,7 @@ module: grove
 version_added: 1.4
 short_description: Sends a notification to a grove.io channel
 description:
-     - The M(grove) module sends a message for a service to a Grove.io
+     - The C(grove) module sends a message for a service to a Grove.io
        channel.
 options:
   channel_token:

lib/ansible/modules/notification/hall.py

@@ -27,7 +27,7 @@ DOCUMENTATION = """
 module: hall
 short_description: Send notification to Hall
 description:
-    - "The M(hall) module connects to the U(https://hall.com) messaging API and allows you to deliver notication messages to rooms."
+    - "The C(hall) module connects to the U(https://hall.com) messaging API and allows you to deliver notication messages to rooms."
 version_added: "2.0"
 author: Billy Kimble (@bkimble) <basslines@gmail.com>
 options:

lib/ansible/modules/notification/rocketchat.py

@@ -28,7 +28,7 @@ DOCUMENTATION = """
 module: rocketchat
 short_description: Send notifications to Rocket Chat
 description:
-    - The M(rocketchat) module sends notifications to Rocket Chat via the Incoming WebHook integration
+    - The C(rocketchat) module sends notifications to Rocket Chat via the Incoming WebHook integration
 version_added: "2.2"
 author: "Ramon de la Fuente (@ramondelafuente)"
 options:

lib/ansible/modules/notification/slack.py

@@ -29,7 +29,7 @@ DOCUMENTATION = """
 module: slack
 short_description: Send Slack notifications
 description:
-    - The M(slack) module sends notifications to U(http://slack.com) via the Incoming WebHook integration
+    - The C(slack) module sends notifications to U(http://slack.com) via the Incoming WebHook integration
 version_added: "1.6"
 author: "Ramon de la Fuente (@ramondelafuente)"
 options:

lib/ansible/modules/notification/sns.py

@@ -26,7 +26,7 @@ DOCUMENTATION = """
 module: sns
 short_description: Send Amazon Simple Notification Service (SNS) messages
 description:
-    - The M(sns) module sends notifications to a topic on your Amazon SNS account
+    - The C(sns) module sends notifications to a topic on your Amazon SNS account
 version_added: 1.6
 author: "Michael J. Schultz (@mjschultz)"
 options: