Windows: Add "special" parameter types to docs (#42853)

* Windows: Add special parameter types

Adding explicit parameter types now exposes this information in the
module documentation, and proves really helpful.

We only do this for non-string types as strings, mostly because strings
are implicit.

PS We also make copyright statements consistent and use #Requires for
explicit library imports

* Type "string" must be type "str"

* A few more Copyright corrections

* More fixes

* Don't add file encoding to Powershell files

* Don't add missing interfacetypes parameter

Otherwise CI demands an incorrect version_added

* Small fix

lib/ansible/modules/windows/win_robocopy.py

@@ -25,10 +25,12 @@ options:
     description:
     - Source file/directory to sync.
     required: yes
+    type: path
   dest:
     description:
     - Destination file/directory to sync (Will receive contents of src).
     required: yes
+    type: path
   recurse:
     description:
     - Includes all subdirectories (Toggles the C(/e) flag to RoboCopy).