remove links to Moderator Contact Form

This is a temporary measure until we can get the form working again.

This has NOT been approved by any of Habitica's staff.
It's just being proposed for consideration.

The changes are:

- remove link from Help menu
- replace link in Contacts page with mailto admin@habitica.com without changing the visible text of the link
- replace link in Tavern sidebar with mailto admin@habitica.com using the visible text from the Contacts page

website/client/src/components/header/menu.vue

@@ -336,10 +336,6 @@
                 href="http://habitica.fandom.com/wiki/Habitica_Wiki"
                 target="_blank"
               >{{ $t('wiki') }}</a>
-              <a
-                class="topbar-dropdown-item dropdown-item"
-                @click="modForm()"
-              >{{ $t('contactForm') }}</a>
             </div>
           </li>
         </b-navbar-nav>