Experimentally add a WIP list

I regularly filter the main agenda view for the CONT tag to see my WIP items, so
it's propably meaningful to have this as extra list.  It's using some space in
the agenda view, though, so let's see how this will turn out.

init.el

@@ -1074,6 +1074,9 @@
                    ((org-agenda-overriding-header "Deadlines")
                     (org-agenda-sorting-strategy '(deadline-up priority-down))
                     (org-deadline-warning-days 30)))
+                  (tags-todo "TODO=\"CONT\""
+                             ((org-agenda-overriding-header "WIP List (TODO=\"CONT\", all items)")
+                              (org-agenda-sorting-strategy '(priority-down category-up))))
                   (tags-todo "-HOLD-SOMEWHEN-DATE-WAIT/-DONE"
                              ((org-agenda-overriding-header "Next Actions List (not scheduled or scheduled in the future)")
                               (org-tags-match-list-sublevels t)