Reduce spacing between textbox and ‘I have’t rec…’

The grouping on this page was weird because these links were two far away from
the associated textbox, and too close to the next textbox.

This commit adds them as parameters to the textbox macro, which means their
relative spacing can be controlled exactly, and thus reduced.

app/assets/stylesheets/components/textbox.scss

@@ -81,3 +81,7 @@
 
 
 }
+
+.textbox-help-link {
+  margin: 5px 0 0 0;
+}