Clarify return value of the sequence lookup

Fixes ansible#17852

lib/ansible/plugins/lookup/sequence.py

@@ -15,6 +15,7 @@
       - 'Arguments can be specified as key=value pair strings or as a shortcut form of the arguments string is also accepted: [start-]end[/stride][:format].'
       - 'Numerical values can be specified in decimal, hexadecimal (0x3f8) or octal (0600).'
       - Starting at version 1.9.2, negative strides are allowed.
+      - Generated items are strings. Use Jinja2 filters to convert items to preferred type, e.g. ``{{ 1 + item|int }}``.
     options:
       start:
         description: number at which to start the sequence
@@ -62,7 +63,9 @@
 
 RETURN = """
   _list:
-    description: generated sequence of numbers or strings
+    description:
+      - A list containing generated sequence of items
+    type: list
 """
 
 from re import compile as re_compile, IGNORECASE