chore: make it clear that the email also works for username

views/login.tpl.html

@@ -37,9 +37,9 @@
                             class="input-default"
                             type="text"
                             id="username"
-                            autocomplete="username"
+                            autocomplete="email"
                             name="username"
-                            placeholder="Username"
+                            placeholder="Email or SlackID"
                             minlength="1"
                             required
                             autofocus