Add link to Facebook group

_locales/en/messages.json

@@ -316,6 +316,9 @@
     "communityTelegramSupport": {
         "message": "Telegram Channel"
     },
+    "communityFacebookSupport": {
+        "message": "Facebook Group"
+    },
     "initialSetupBackupAndRestoreApiVersion": {
         "message": "<span style=\"color: red\">Backup and restore functionality disabled.</span>  You have firmware with API version <span style=\"color: red\">$1</span>, backup and restore requires <span style=\"color: #37a8db\">$2</span>.  Please backup your settings via the CLI, see INAV documentation for procedure."
     },

tabs/landing.html

@@ -8,6 +8,7 @@
         </div>
         <div class="community">
             <ul class="communityTelegramSupport"><a href="https://t.me/INAVFlight" target="_blank"><i class="fa fa-telegram" aria-hidden="true"></i><span i18n="communityTelegramSupport"></span></a></ul>
+            <ul class="communityFacebookSupport"><a href="https://www.facebook.com/groups/INAVOfficial" target="_blank"><i class="fa fa-facebook" aria-hidden="true"></i><span i18n="communityFacebookSupport"></span></a></ul>
             <ul class="communitySlackSupport"><a href="https://publicslack.com/slacks/inavflight/invites/new" target="_blank"><i class="fa fa-slack" aria-hidden="true"></i><span i18n="communitySlackSupport"></span></a></ul>
             <ul class="communityRCGroupsSupport"><a href="https://www.rcgroups.com/forums/showthread.php?2495732-Cleanflight-iNav-%28navigation-rewrite%29-project" target="_blank"><i class="fa fa-users" aria-hidden="true"></i><span i18n="communityRCGroupsSupport"></span></a></ul>
         </div>