Update migration.md

Adds description to callouts

diff --git a/migration.md b/migration.md
index 01eef8faf1573c984955b9cf8b0cb25f2372e77e..330ba8a5de7b5db2772536e843cd6a24f1f72c7b 100644 (file)
--- a/migration.md
+++ b/migration.md
@@ -390,6 +390,8 @@ Version 2 (Inky markup)
 </callout>
 ```
 
+Callouts used to only be applicable to a `<td>`. In Foundation for Emails 2, you can wrap a callout around a `<row>` or the content inside a `<column>`.
+
 ***
 ## NEW
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