Use the CodeMirror editor in the slide application

customize.dist/messages.js

@@ -69,5 +69,20 @@ define(['/customize/languageSelector.js',
         '*/'
     ].join('');
 
+    messages.slideInitialState = [
+        '# CryptSlide\n',
+        '* This is a zero knowledge realtime collaborative editor.\n',
+        '* What you type here is encrypted so only people who have the link can access it.\n',
+        '* Even the server cannot see what you type.\n',
+        '* What you see here, what you hear here, when you leave here, let it stay here.\n',
+        '\n',
+        '---',
+        '\n',
+        '# How to use\n',
+        '1. Write your slides content using the markdown syntax\n',
+        '2. Separate your slides with ---\n',
+        '3. Click on the "Play" button to see the result'
+    ].join('');
+
     return messages;
 });