feat: added learn page

- added sections to the lesson to handle multiple sesions like examples and exercises
- added livecode integration to lesson pages
- autosave and submiting the answers is not done yet

community/public/css/style.less

@@ -235,7 +235,7 @@ section.lightgray {
 
 // LiveCode editor
 
-.livecode-editor-large {
+.livecode-editor {
 
   .CodeMirror {
     border: 1px solid #ddd;
@@ -302,3 +302,7 @@ section.lightgray {
 #hero h1 {
   color: black !important;
 }
+
+.lesson {
+  margin: 20px 0px 20px 50px;
+}