Add example or topic guide about the AEC error

[nabobalis]

Short exposure times and maybe how to correct it?

[nabobalis]

@hayesla and @aringlis, we (I and @wtbarnes) spoke to Meng and he suggested an example or document that explains the AEC problem, the pit falls, and if there are ways to avoid introducing it when looking at data.

I think that you two are best placed to work on a document we could add to the aiapy documentation.

Would either of you be willing to help?