AP Science Lead -- Update Nightly Flow diagram

There are several things that came up in talking through the current dataflow diagram in the draft branch of LDM-151, several updates were identified. I'm assigning this to Eric Bellm, but I'm happy to have him hand it off to me or someone else.

• Alert Generation box needs template as input
• Between Alert Generation and Alert Distribution, the box says DIAObject, but that's not strictly true since now postage stamps exist with each DIASource
• Alert distribution is shown as a tan box which implies that it is a pipeline, but in reality is that it is a completely separate system. In fact, I image the system as function by having Alert Generation post the "alerts" directly to that system.