idea: give helpful warnings if defaults not changed before launching an experiment

[deargle]

There seem to be dozens of minutiae to remember before launching a new experiment. I want to log warnings (not throw errors) when some of them seem to have been forgotten, such as the university.png, favicon.ico, and page titles not having been changed, and perhaps when some defaults in config.txt have not been changed.

[deargle]

... and the pre-accept text in ad.html 🤦