[Documentation] describe cases when `configure` may fail

[flpvsk]

failCallback – optional function that calls when something goes wrong on editor setup.

Users might want to know when does configure fail and why?

[lahmatiy]

All those fails is about wrong values in config. If you want to know why configuration doesn't work, you should provide failCallback

[lahmatiy]

It's something about validation. For example editor or cmd should be set

[flpvsk]

How about

failCallback – optional function that's called if there is something wrong with config.

[lahmatiy]

👍