Removed TOC from controller/components section.

Replaced the TOC at the beginning of the Controller/Components section and replaced it with a link to the primary section on Components which contains the same TOC anyway. Reworded the first two paragraphs in doing so.

~ Refs #1149 where the general issue of repeating content is discussed. This commit only addresses one such instance. I guess it shows an example of the alternative approach w.r.t #1149.