Template:Easy CSS image crop 2/doc

This is an earlier form of Template:Easy CSS image crop that uses pixel sizes for the crops instead of percentages, which is a little unintuitive when the base image you're cropping from changes based on the desired end width.

For the crop parameters, note that since we're going for a desired width, the size of the image being cropped from will vary depending on what  and   are set to. As such, these should be set before playing with  and. All default to 0, which means nothing is cropped from that side.