Issue #22558: Add remaining doc links to source code for Python-coded modules.
Reformat header above separator line (added if missing) to a common format.
Patch by Yoni Lavi.
diff --git a/Doc/library/signal.rst b/Doc/library/signal.rst
index d02a0a8..61252ce 100644
--- a/Doc/library/signal.rst
+++ b/Doc/library/signal.rst
@@ -4,6 +4,7 @@
 .. module:: signal
    :synopsis: Set handlers for asynchronous events.
 
+--------------
 
 This module provides mechanisms to use signal handlers in Python.