Add Notes and Titled Containers to ETLs

I find that my ETLs are often big, with multiple endpoints; so when I come back it takes me some time to catch up with what I did. I think that adding some text notes to the ETL view would make it easier to evaluate what I, or one of my coworkers, have done. As for titled containers, they would allow a user to draw a boundary around a section of an ETL and label the purpose of that section.