Fix broken README.md url

pages/grade-calc/index.html

@@ -62,7 +62,7 @@
         <h1><a href="/">PaulW.XYZ</a> / <a href="/pages/">Pages</a> / Grade Calculator</h1>
         <hr>
         <h2>About</h2>
-        Check out the <a href="https://github.com/lambdapaul/pages/blob/master/grade-calc/README.md">README.md</a> file
+        Check out the <a href="https://github.com/lambdapaul/www/blob/master/pages/grade-calc/README.md">README.md</a> file
         to learn more about the configuration structure.
         <h3>Usage</h3>
         <ol>
@@ -124,4 +124,4 @@
     </script>
 </body>
 
-</html>
+</html>