Provide better instructions for the Pass Through blending mode

For groups, Pass Through is Normal!

For groups, Normal is Abnormal!

That paradox made it hard to me to understand Adobe’s user manual on this topic (here), which seemed to be describing the opposite of what actually happens.

I’ve attempted a clarified version below (which would constitute a separate subsection, specific to groups):

Specify a blending mode for a group

When you choose the Normal blending mode for a group, you adopt the normal order in which the image components are put together. Normally, all of the layers in the group are put together first. The composite group is then treated as a single image and blended with the rest of the image using the selected blending mode. Therefore, none of the adjustment layers or layer blending modes inside the group will apply to layers outside the group.

By default, instead of Normal, the blending mode for a group is Pass Through. The group’s adjustment layers and layer blending modes are applied first, before any compositing, and therefore affect layers outside as well as inside the group.