Add information about updating 'compared to control AE' when editing metagenotypes

[CuzickA]

Add text reminding curators to manually update the AE compared to control metagenotypes annotated.

We might add this to https://canto.phi-base.org/docs/genotypes in this section

under the

What do you think @jseager7

[jseager7]

I'm going to put this on hold until I know how difficult it will be to fix the problem of updating metagenotypes in annotation extensions automatically. It's not likely to be an easy thing for curators to remember to do manually, we can't really guarantee they'll read the documentation in enough detail to notice this, and even if they do know to do it, it could mean a lot of frustration when there are lots of annotations to fix.