Better documentation for how a resourceref works (#96)

<!-- This change is generated by MagicModules. -->
/cc @rambleraptor

plugins/modules/gcp_sql_database.py

@@ -40,30 +40,33 @@ requirements:
 - requests >= 2.18.4
 - google-auth >= 1.3.0
 options:
-  state:
-    description:
-    - Whether the given object should exist in GCP
-    choices:
-    - present
-    - absent
-    default: present
-  charset:
-    description:
-    - The MySQL charset value.
-    required: false
-  collation:
-    description:
-    - The MySQL collation value.
-    required: false
-  name:
-    description:
-    - The name of the database in the Cloud SQL instance.
-    - This does not include the project ID or instance name.
-    required: true
-  instance:
-    description:
-    - The name of the Cloud SQL instance. This does not include the project ID.
-    required: true
+    state:
+        description:
+            - Whether the given object should exist in GCP
+        choices: ['present', 'absent']
+        default: 'present'
+    charset:
+        description:
+            - The MySQL charset value.
+        required: false
+    collation:
+        description:
+            - The MySQL collation value.
+        required: false
+    name:
+        description:
+            - The name of the database in the Cloud SQL instance.
+            - This does not include the project ID or instance name.
+        required: false
+    instance:
+        description:
+            - The name of the Cloud SQL instance. This does not include the project ID.
+            - 'This field represents a link to a Instance resource in GCP. It can be specified
+              in two ways. You can add `register: name-of-resource` to a gcp_sql_instance task
+              and then set this instance field to "{{ name-of-resource }}" Alternatively, you
+              can set this instance to a dictionary with the name key where the value is the name
+              of your Instance.'
+        required: true
 extends_documentation_fragment: gcp
 '''