Bicep deployment template lacks an embedding model

[andrewDoing]

An embedding model is not deployed as part of the bicep template. This means that the indexing script won't work out of the box without manually deploying an embedding model and setting it in configuration.

EDIT: I'm seeing now that the default embedding model is a sentence transformer, all-mpnet-base-v2. I don't see where it gets deployed to AML, so that would still be nice if thats the preferred default.

Also when I ran the indexing script, it seemed like it was working. If there isn't an embedding model deployed, it should error out and alert the user.