feat: Add California housing tutorial.

Author: mchav

_includes/footer.html

@@ -10,7 +10,7 @@
     <div class="container">
       <div class="row">
         <div class="col s10 offset-s2">
-          Copyright &copy; 2017, all the <strong>dataHaskell</strong> contributors
+          Copyright &copy; 2025, all the <strong>dataHaskell</strong> contributors
         </div>
       </div>
     </div>