Add a section for notes

It would be great to have a section for private personal notes. For instance, I come back after a few days to a campaign and there's many things i don't remember, so it'd be nice to have that so that I don't have to read a lot of text to remember everything that was going on and ideas I had.

I know i could just have a notepad or something, but it's harder to manage when you're running multiple campaigns.