Add cross-reference hyperlinks

Created by: seancolsen

Lot's of places in the User Guide have instructions like this:

See the Email section of this book

And most of these places don't have any sort of hyperlinks to help the reader find their way to that section. We should improve this content by adding hyperlinks.

Tips:

• Find offending content with this command

  $ grep -Prin '(see|refer\sto|go\sto|check\sout|read)\sthe\s(.{0,50}\s)?(chapter|section|page)' docs

• Follow the internal URL standards when fixing content