Issue #7078:  _struct.__doc__ was being ignored.  Import it into struct.
Also add description of '?' struct format character.  Thanks Gabriel
Genellina for the patch.
diff --git a/Lib/struct.py b/Lib/struct.py
index 3784c05..b022355 100644
--- a/Lib/struct.py
+++ b/Lib/struct.py
@@ -1,2 +1,3 @@
 from _struct import *
 from _struct import _clearcache
+from _struct import __doc__