offloaded templates/core/_partials/_forthcoming.html to inject in any applet or other feature under construction; used immediately in Contacts billboard applet; styles updated accordingly

src/static_src/scss/_base.scss

@@ -439,6 +439,16 @@ body {
     }
 }
 
+.forthcoming {
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    transform: translate(-50%, -50%);
+    text-align: center;
+    font-style: italic;
+    opacity: 0.6;
+}
+
 #id_guard_portal {
     display: none;
     position: fixed;