Fix obsolete crispy-forms and contact reference

We no longer use crispy-forms, so we don't have any "customizations"
of it.  Also, we never used Jabber, the IRC channel has been
discontinued and we prefer mailing lists to direct, person e-mails, so
this wording was also changed.

python/nav/web/templates/styleguide.html

@@ -411,8 +411,8 @@ <h3 class="underline">Forms</h3>
       </ul>
 
       <p>
-        There are many customizations done to the crispy forms. Basically, if you
-        need to create forms - ask on mail/jabber/irc.
+        Use existing forms as examples for how to build your own.  If you have questions, ask them
+        on the NAV mailing lists or GitHub discussion forums.
       </p>
 
       {% include 'custom_crispy_templates/flat_form.html' with form=form1 %}