Fix plugins (names, constants, FQCNs in examples) (#722)

* cobbler inventory: fix NAME

* oc transport: fix transport name

* Inventory plugins: fix plugin identifications

* Use FQCN in lookup plugin examples.

* Use FQCN in callback plugins.

* Add changelog fragment.

* Adjust documentation.

* Fix lookup plugin linting errors.

* Fix quotes.

plugins/inventory/docker_machine.py

@@ -24,7 +24,7 @@ DOCUMENTATION = '''
         plugin:
             description: token that ensures this is a source file for the C(docker_machine) plugin.
             required: yes
-            choices: ['docker_machine']
+            choices: ['docker_machine', 'community.docker.docker_machine']
         daemon_env:
             description:
                 - Whether docker daemon connection environment variables should be fetched, and how to behave if they cannot be fetched.
@@ -54,7 +54,7 @@ DOCUMENTATION = '''
 
 EXAMPLES = '''
 # Minimal example
-plugin: docker_machine
+plugin: community.docker.docker_machine
 
 # Example using constructed features to create a group per Docker Machine driver
 # (https://docs.docker.com/machine/drivers/), e.g.:

plugins/inventory/docker_swarm.py

@@ -26,11 +26,11 @@ DOCUMENTATION = '''
           I(nonleaders) - all nodes except the swarm leader."
     options:
         plugin:
-            description: The name of this plugin, it should always be set to C(docker_swarm) for this plugin to
+            description: The name of this plugin, it should always be set to C(community.docker.docker_swarm)
-                         recognize it as it's own.
+                         for this plugin to recognize it as it's own.
             type: str
             required: true
-            choices: docker_swarm
+            choices: [ docker_swarm, community.docker.docker_swarm ]
         docker_host:
             description:
                 - Socket of a Docker swarm manager node (C(tcp), C(unix)).
@@ -101,20 +101,20 @@ DOCUMENTATION = '''
 
 EXAMPLES = '''
 # Minimal example using local docker
-plugin: docker_swarm
+plugin: community.docker.docker_swarm
 docker_host: unix://var/run/docker.sock
 
 # Minimal example using remote docker
-plugin: docker_swarm
+plugin: community.docker.docker_swarm
 docker_host: tcp://my-docker-host:2375
 
 # Example using remote docker with unverified TLS
-plugin: docker_swarm
+plugin: community.docker.docker_swarm
 docker_host: tcp://my-docker-host:2376
 tls: yes
 
 # Example using remote docker with verified TLS and client certificate verification
-plugin: docker_swarm
+plugin: community.docker.docker_swarm
 docker_host: tcp://my-docker-host:2376
 validate_certs: yes
 ca_cert: /somewhere/ca.pem
@@ -122,7 +122,7 @@ client_key: /somewhere/key.pem
 client_cert: /somewhere/cert.pem
 
 # Example using constructed features to create groups and set ansible_host
-plugin: docker_swarm
+plugin: community.docker.docker_swarm
 docker_host: tcp://my-docker-host:2375
 strict: False
 keyed_groups: