No documentation on how to update rows

[9662]

As seen on a number of issues, most recently #1302, getting the grid view to refresh after programmatically updating the data is non-obvious and fraught with traps.

I have personally just been caught by the problem that @ravenscar highlights on his comment there, namely that I was keeping the hash value in the data.

At a minimum, an example with a detailed explanation would be nice to have, since the documentation (specifically example 316) doesn't quite cover it and details about update notifications are a bit lacking.

With that said, I do appreciate the job you've done, thanks for sharing it!