Update navigation menu in notes.html

Author: Coding331

notes.html

@@ -141,8 +141,7 @@ <h1>Study Notes</h1>
     <nav>
         <a href="index.html">Home</a>
         <a href="library.html">Study Guides</a>
-        <a href="physics.html">Physics</a>
-        <a href="math.html">Mathematics</a>
+        <a href="notes.html">Notes</a>
     </nav>
     <div class="container">
         <h2>Your Notes</h2>