add stub entry about new approach for skeuomorphic theming to the migration guide

diff --git a/docs/migration.md b/docs/migration.md
index c5416b6634cd61d8723a4901ea917d4b79a86607..6904a61238097d0110ecd26d2b5c5a3f83115559 100644 (file)
--- a/docs/migration.md
+++ b/docs/migration.md
@@ -19,6 +19,7 @@ For a broader overview, see [what's new](http://blog.getbootstrap.com/DEAD-LINK-
 - Refactored nearly all components to use more unnested classes instead of children selectors.
 - Non-responsive usage of Bootstrap is no longer supported.
 - Dropped the online Customizer in favor of more extensive setup documentation.
+- Replaced the separate optional theme with...
 
 ## Major class changes