editor: Completely remove title using the title dec button

app/static/scripts/editor.js

@@ -107,9 +107,9 @@ function editor_set_title(event, level, diff)
         if(count < line.length && line[count] == ' ') contents_index++;
         let contents = line.slice(contents_index);
 
-        if(level > 0) {
+        if(level > 0 || count == 1 && diff == -1) {
             /* Remove the title if the corresponding level is re-requested */
-            if(count == level)
+            if(count == level || count == 1 && diff == -1)
                 return contents;
             /* Otherwise, add it */
             else