the possibility to include a file in a migration

[charleybebbaag]

It would be nice to have the possibility to include a file in a migration.
Something like the command :r of sqlcmd (https://docs.microsoft.com/en-us/sql/tools/sqlcmd-utility?view=sql-server-2017)

Use case:
The procedures / functions / triggers / views are mantained in their own files. When such an object is released, a new migration is created that includes the file that contains the object.
Advantage: when I debug an issue and I want to see the changes for a procedure, it is easy to do so by using the history option of svn/github/hg.