Fix pickletools doc for NEWFALSE. (GH-9432)

Also make docs for NEWFALSE and NEWTRUE more consistent
with docs for other opcodes.

Lib/pickletools.py

diff --git a/Lib/pickletools.py b/Lib/pickletools.py
index 8486cbf..ed8bee3 100644
--- a/Lib/pickletools.py
+++ b/Lib/pickletools.py
@@ -1325,9 +1325,7 @@
       stack_before=[],
       stack_after=[pybool],
       proto=2,
-      doc="""True.
-
-      Push True onto the stack."""),
+      doc="Push True onto the stack."),
 
     I(name='NEWFALSE',
       code='\x89',
@@ -1335,9 +1333,7 @@
       stack_before=[],
       stack_after=[pybool],
       proto=2,
-      doc="""True.
-
-      Push False onto the stack."""),
+      doc="Push False onto the stack."),
 
     # Ways to spell Unicode strings.