Added support for FIXME

src/articles/cheat_sheets/Markdown_cheat_sheet.md

@@ -24,6 +24,8 @@ Now some inline markup like _italics_,  **bold**, ~~strike through~~ and `code()
 
 ![picture alt](http://nuclearpixel.com/content/icons/2010-02-09_stellar_icons_from_space_from_2005/earth_128.png "Title is optional")
 
+Want to mark something in your article to fix later? Write FIXME. This will create a yellow fixme marker.
+
 > Blockquotes are like quoted text in email replies
 >> And, they can be nested
 

src/client/less/markdown.less

@@ -99,4 +99,11 @@
     background-color: #F8F8F8;
   }
 
+  .fixme {
+    border: 1px solid @colorText;
+    border-radius: 4px;
+    background-color: #ffd703;
+    padding: 0 4px;
+  }
+
 }

src/server/logic/RenderService.php

@@ -16,6 +16,10 @@ class RenderService {
     public function renderMarkdown($markdownText, $isEditMode) {
         require_once __DIR__ . '/../lib/parsedown/Parsedown.php';
         $html = Parsedown::instance()->text($markdownText);
+
+        // Support `FIXME`
+        $html = preg_replace('/(^|\\W)FIXME(\\W|$)/', '$1<span class="fixme">FIXME</span>$2', $html);
+
         if ($isEditMode) {
             // Append `?edit` to local links (in order to stay in edit mode)
             $html = preg_replace_callback('|(<a href="([^"]+))"|',