user doc sections

Home.md

@@ -8,6 +8,10 @@
     * [[ReCodEx goals|Introduction#recodex-goals]]
     * [[Terminology|Introduction#terminology]]
 * [[User documentation]]
+    * [[Student|User documentation#student]]
+    * [[Lecturer|User documentation#lecturer]]
+    * [[Author of exercise|User documentation#author-of-exercise]]
+    * [[Administrator|User documentation#administrator]]
 * [[Overall architecture]]
     * [[Description|Overall architecture#description]]
     * [[Communication|Overall architecture#communication]]