DOC: move extractall ref point

Author: jreback

doc/source/whatsnew/v0.18.0.txt

@@ -235,11 +235,11 @@ In summary, ``extract(expand=True)`` always returns a ``DataFrame``
 with a row for every subject string, and a column for every capture
 group.
 
+.. _whatsnew_0180.enhancements.extractall:
+
 Addition of str.extractall
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-.. _whatsnew_0180.enhancements.extractall:
-
 The :ref:`.str.extractall <text.extractall>` method was added
 (:issue:`11386`).  Unlike ``extract`` (which returns only the first
 match),