fix: Error on entering a document that doesn't exist

static/style/main.css

@@ -70,6 +70,10 @@ pre {
     padding-left: 20px;
 }
 
+.grayed {
+    color: gray;
+}
+
 
 .editor-toolbar {
     border-top: 0px solid #444;

templates/main.html

@@ -26,9 +26,13 @@
             <a href="/{{ path }}?edit">Edit</a>
             {% endif %}
 
+            {% if content is not none %}
                 {% autoescape false %}
                 {{ markdown(content, extensions=['extra']) }}
                 {% endautoescape %}
+            {% else %}
+                <p class="grayed">This document doesn't exist</p>
+            {% endif %}
         {% else %}
             <form method="POST" action="/{{ path }}">
                 <textarea id="markdown-textarea" name="text">{{ content }}</textarea>