Text Size SC

I added this to clarify functionality.

Simply Put: A person can zoom or shrink text only. Pictures, diagrams and
videos don't change. @@A Key functionality to preserve is that complete
lines of text fit within the viewport. For any block of text, the last word
of a line is the immediate predecessor of the first word in the next line
in reading order. No exceptions. Also, text fits within bounding boxes,
lines, and columns if present. Finally, margins do not enlarge with
zooming.@@