Address minor "confusing" typo in migration docs

doc/development/migration_style_guide.md

@@ -39,7 +39,7 @@ Changes to the schema should be committed to `db/structure.sql`. This
 file is automatically generated by Rails, so you normally should not
 edit this file by hand. If your migration is adding a column to a
 table, that column will be added at the bottom. Please do not reorder
-columns manually for existing tables as this will cause confusing to
+columns manually for existing tables as this will cause confusion to
 other people using `db/structure.sql` generated by Rails.
 
 When your local database in your GDK is diverging from the schema from