updated pictures and added big-picture

[Baasie]

The following feedback is from Chris: Also, a couple of comments about the "Picture that explains almost everything" - it would be good if the caption included what kind of event storming it was for. Also, there isn't a picture that explains everything for the big picture event storming.

Updated the picture, also based on the feedback @NTCoding gave to @pimsmeets his comment.

• fixed a typo.

Wil ask Chris to join this thread :)