Use file documentation fragement for the copy module

lib/ansible/utils/module_docs_fragments/files.py

@@ -21,7 +21,6 @@ class ModuleDocFragment(object):
     # Standard files documentation fragment
     DOCUMENTATION = """
 options:
-options:
   path:
     description:
       - 'path to the file being managed.  Aliases: I(dest), I(name)'

library/files/copy

@@ -83,6 +83,7 @@ options:
         defaults.
     required: false
     version_added: "1.5"
+extends_documentation_fragment: files
 author: Michael DeHaan
 notes:
    - The "copy" module recursively copy facility does not scale to lots (>hundreds) of files.