Fix atexitmodule doc (GH-21456)
diff --git a/Modules/atexitmodule.c b/Modules/atexitmodule.c
index 8cef64c..fd47ddd 100644
--- a/Modules/atexitmodule.c
+++ b/Modules/atexitmodule.c
@@ -309,7 +309,7 @@
/* Initialization function. */
PyDoc_STRVAR(atexit__doc__,
-"allow programmer to define multiple exit functions to be executed\
+"allow programmer to define multiple exit functions to be executed\n\
upon normal program termination.\n\
\n\
Two public functions, register and unregister, are defined.\n\