[doc] Add references to tools/_deprecate.py

Change-Id: I037fb11442e989746147d7d76ee7fd0d1a8e407c
---
M pywikibot/tools/_deprecate.py
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/pywikibot/tools/_deprecate.py b/pywikibot/tools/_deprecate.py
index cd4b4d9..8af5878 100644
--- a/pywikibot/tools/_deprecate.py
+++ b/pywikibot/tools/_deprecate.py
@@ -316,9 +316,10 @@
         def my_function(): pass
         # ignores 'foo' keyword no longer used by my_function
 
-    deprecated_args decorator should be used in favour of this
-    deprecate_arg decorator but it is held to deprecate args which become
-    a reserved word in future Python releases and to prevent syntax errors.
+    :func:`deprecated_args` decorator should be used in favour of this
+    ``deprecate_arg`` decorator but it is held to deprecate args which
+    become a reserved word in future Python releases and to prevent
+    syntax errors.
 
     :param old_arg: old keyword
     :param new_arg: new keyword

