Update python/tskit/tables.py

Co-authored-by: Peter Ralph <petrel.harp@gmail.com>

Author: hyanwong

python/tskit/tables.py

@@ -4036,8 +4036,8 @@ def concatenate(
         acts *in place* to alter the data in this :class:`TableCollection`.
 
         .. note::
-            To add gaps between the concatenated tables, use :meth:`shift` or
-            to remove gaps, use :meth:`trim` before concatenating.
+            To add gaps between the concatenated tables, use :meth:`shift` before
+            concatenating; to remove gaps, use :meth:`trim`.
 
         :param TableCollection other: The other table collection to add to the right
             of this one.