show/hide section content

using Bootstrap Collapse plugin
extract fragment id, show this element and scroll to it on page open
moved show/hide link text swap to event handler
adding comments above main code paths
only show pre-footer if it has content
changed to "Show"
style changes on label resource within a topic section
removing top margin from .section
need some additional bottom margin between .activity list items
styles to support positioning 'edit summary' link beside topic title