Improve aws_ec2 plugin documentation (#37689)

* Better formatting
* More examples

lib/ansible/plugins/inventory/aws_ec2.py

@@ -56,8 +56,6 @@ DOCUMENTATION = '''
 '''
 
 EXAMPLES = '''
-simple_config_file:
-
 plugin: aws_ec2
 boto_profile: aws_profile
 regions: # populate inventory with instances in these regions
@@ -74,21 +72,28 @@ simple_config_file:
 # ignores 403 errors rather than failing
 strict_permissions: False
 hostnames:
-      - tag:Name=Tag1,Name=Tag2
+  - tag:Name=Tag1,Name=Tag2  # return specific hosts only
   - tag:CustomDNSName
   - dns-name
 
-    # constructed features may be used to create custom groups
+# keyed_groups may be used to create custom groups
 strict: False
 keyed_groups:
+  # add e.g. x86_64 hosts to an arch_x86_64 group
   - prefix: arch
     key: 'architecture'
-        value: 'x86_64'
+  # add hosts to tag_Name_Value groups for each Name/Value tag pair
   - prefix: tag
     key: tags
-        value:
+  # add hosts to e.g. instance_type_z3_tiny
-          "Name": "Test"
+  - prefix: instance_type
-
+    key: instance_type
+  # create security_groups_sg_abcd1234 group for each SG
+  - key: 'security_groups|json_query("[].group_id")'
+    prefix: 'security_groups'
+  # create a group for each value of the Application tag
+  - key: tag.Application
+    separator: ''
 '''
 
 from ansible.errors import AnsibleError, AnsibleParserError