Thinking behind having a separate Migrations Service isn't clear

[IEvangelist]

Watch this video and update the docs in question, with related/relevant information.

Summary by @CamSoper:

• Critical that Connect to SQL doc, EF Migrations doc, and EF Seeding doc are separate docs.

• Critical that per EF Migrations doc (which was in turn based on this sample), we show a separate Migrations service that runs once and shuts down.

• Builds a demo that is more or less exactly the same as what we show in the three docs, except they put the migration/seeding logic in the application code itself.

• Shows how to connect SSMS to the SQL Server container and view the database.

[CamSoper]

@JamesNK I made a doc using your sample but we've heard some feedback that they don't see why the migrations need to live in their own separate service. Do we have any guidance on that?

Regarding connecting a DBMS client of some kind, I'd like a doc like that but the way he did it was by manually setting the password in his dev environment with dotnet secrets. Do we have any feedback on that? @IEvangelist? @JamesNK?