Add more friendly error help for global APIs used at top-level code

[toolness]

In #1130 we added some logic that attempts to notice when people use p5's global APIs in top-level code, but it looks like there are some ways to improve it:

• Based on createGraphics() undefined #1237 it looks like we might want to detect if createGraphics was called. Perhaps also the other p5 methods that start with create, e.g. createCanvas?
• Based on PI is not defined before setup()! #903 it looks like folks will (understandably) expect P5's global constants to be defined during page load, so detecting for those would be good too.
• When @limzykenneth responded to createGraphics() undefined #1237 he linked to a helpful FAQ question, which would be nice for the friendly error logger to link to.

Another possibility for the first two is to actually embed an entire (auto-generated) list of every single public p5 symbol in the debug builds of p5.js, and match any pre-load exceptions thrown to it. This might have the downside of matching on too many exceptions, but it's also much more likely to help beginners... Hmm.