Commodity Model Updates: Diagram and Doc

This is great, thanks Brandon. I made a couple edits, and I'm sure there's more edits for clarity and examples that will be added later, but for now this captures the information out of the working group.

I've revised the main commodity model doc: https://openlmis.atlassian.net/wiki/display/OP/Medical+Commodities%3A+OpenLMIS+Model+for+GS1

Please review, and let me know if there are any more revisions it needs. Otherwise we can mark this ticket Done, I hope.

After this I want to work next on the other pieces of documentation in separate tickets in the GS1 epic for 3.0.

Did the GDD review the working group wanted and out of that entered tickets:

I'm passing this ticket back to you for your quick feedback. Please pass back to me and I can continue writing once you have done 2 things, pretty please:
1) Answer the questions I posted in comments in the wiki: https://openlmis.atlassian.net/wiki/display/OP/Beta+to+3.0+changes
2) Please read and leave any feedback about my new re-write of the main commodity doc: https://openlmis.atlassian.net/wiki/display/OP/Medical+Commodities%3A+OpenLMIS+Model+for+GS1

I believe I'll be able to finish that main commodity doc, based on your input. I also believe that I can write enough documentation that we will achieve many of the ToDo tickets in the GS1 epic for 3.0.

I went through that whole wiki page, and it mostly made sense to me. I left comments in the wiki where I had questions.

Passing this ticket back to you. It's possible this ticket can be marked Done since you're creating a new ticket for implementing some of the renaming/revisions. You also mentioned the need to "update the main commodity doc" so it's your call if that needs to happen as part of this ticket or if you make that part of or or a new ticket.

ALSO, we need to review the GS1 Epic to determine what really needs to happen for those tickets marked 3.0 and how much this documentation is already done.