add motd schema and motd editor

app/templates/mod/motd.html

@@ -0,0 +1,17 @@
+{% from 'common/macros.html' import babycode_editor_component %}
+{% extends 'base.html' %}
+{% block title %}editing MOTD{% endblock %}
+{% block content %}
+<div class="darkbg settings-container">
+  <h1>Edit Message of the Day</h1>
+  <p>The Message of the Day will show up on the main page and in every topic.</p>
+  <form method="POST">
+    <label for="title">Title</label>
+    <input name="title" id="title" type="text" required autocomplete="off" placeholder="Required" value="{{ current.title }}"><br>
+    <label for="body">Body</label>
+    {{ babycode_editor_component('body', ta_placeholder='MOTD body (required)', banned_tags=['img', 'spoiler'], prefill=current.body_original_markup) }}
+    <input type="submit" value="Save">
+    <input class="critical" type="submit" formaction="{{ url_for('mod.motd_delete') }}" value="Delete MOTD" formnovalidate {{"disabled" if not current else ""}}>
+  </form>
+</div>
+{% endblock %}

app/templates/mod/panel.html

@@ -6,6 +6,7 @@
   <ul>
     <li><a href="{{ url_for('mod.user_list') }}">User list</a></li>
     <li><a href="{{ url_for('mod.sort_topics') }}">Sort topics</a></li>
+    <li><a href="{{ url_for('mod.motd_editor') }}">Message of the Day</a></li>
   </ul>
 </div>
 {% endblock %}