Content update and a few changes

Big Makefile update
Small summary and table of contents update
Also some content, apprentice and matrix(.org)

assets/main.scss

@@ -15,10 +15,13 @@ body {
   }
   a:hover %headings {
     text-decoration: underline;
-    color: blue;
+    color: cyan;
   }
   a {
     text-decoration: none;
+    color: cyan;
+  }
+  a li {
     color: lime;
   }
 }