[3.12] GH-116218 Docs: Add availability information for the 'resource' module (GH-116256) (#116533)

GH-116218 Docs: Add availability information for the 'resource' module (GH-116256)

Add availability data to 'resource' module Docs
(cherry picked from commit 03f86b1)

Co-authored-by: Kerim Kabirov <39376984+Privat33r-dev@users.noreply.github.com>

Author: miss-islington

Doc/library/resource.rst

@@ -177,6 +177,8 @@ platform.
 
    The largest area of mapped memory which the process may occupy.
 
+   .. availability:: FreeBSD >= 11.
+
 
 .. data:: RLIMIT_AS