DOC: Add explanation of sort=false for groupby (#52736)

Co-authored-by: Marco Edward Gorelli <[email protected]>

Author: raanasn

doc/source/user_guide/groupby.rst

@@ -196,7 +196,7 @@ only verifies that you've passed a valid mapping.
 GroupBy sorting
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-By default the group keys are sorted during the ``groupby`` operation. You may however pass ``sort=False`` for potential speedups:
+By default the group keys are sorted during the ``groupby`` operation. You may however pass ``sort=False`` for potential speedups. With ``sort=False`` the order among group-keys follows the order of appearance of the keys in the original dataframe:
 
 .. ipython:: python
 

pandas/core/shared_docs.py

@@ -130,7 +130,8 @@
 sort : bool, default True
     Sort group keys. Get better performance by turning this off.
     Note this does not influence the order of observations within each
-    group. Groupby preserves the order of rows within each group.
+    group. Groupby preserves the order of rows within each group. If False,
+    the groups will appear in the same order as they did in the original DataFrame.
     This argument has no effect on filtrations (see the `filtrations in the user guide
     <https://pandas.pydata.org/docs/dev/user_guide/groupby.html#filtration>`_),
     such as ``head()``, ``tail()``, ``nth()`` and in transformations