add note on how to avoid service start in apt

lib/ansible/modules/packaging/os/apt.py

@@ -139,9 +139,9 @@ requirements:
    - aptitude (before 2.4)
 author: "Matthew Williams (@mgwilliams)"
 notes:
-   - Three of the upgrade modes (C(full), C(safe) and its alias C(yes))
-     required C(aptitude) up to 2.3, since 2.4 C(apt-get) is used as a
-     fall-back.
+   - Three of the upgrade modes (C(full), C(safe) and its alias C(yes)) required C(aptitude) up to 2.3, since 2.4 C(apt-get) is used as a fall-back.
+   - apt starts newly installed services by default, this is what the underlying tooling does,
+     to avoid this you can set the ``RUNLEVEL`` environment variable to 1.
 '''
 
 EXAMPLES = '''
@@ -150,10 +150,13 @@ EXAMPLES = '''
     name: foo
     update_cache: yes
 
+- name: Install apache service but avoid starting it immediately
+  apt: name=apache2 state=present
+  environment:
+    RUNLEVLEL: 1
+
 - name: Remove "foo" package
-  apt:
-    name: foo
-    state: absent
+  apt: name=foo state=absent
 
 - name: Install the package "foo"
   apt:
@@ -222,6 +225,7 @@ EXAMPLES = '''
 - name: Remove dependencies that are no longer required
   apt:
     autoremove: yes
+
 '''
 
 RETURN = '''