Data storage concerns and warnings

[cansavvy]

Right now there are two storage strategies: github or googlesheets.

Github has the 100MB constraint (assuming avoiding git lfs)
Googlesheet may break at a certain file size as well.

1. we need warnings when files get too big
2. Maybe we need a third storage alternative that is not so fragile for "power" users?

Some rough numbers:

So far our GitHub metrics file has collected 1026 rows of data since Jan.
Apparently for this kind of data based on my rough calculations it would not be until 1.8 million rows that we would get to 100MB. And 1.8 million rows would probably break Googlesheets too