Updated footer

- The footer now includes a CC-BY clarification
- The footer now clarifies that the website's contents are not AI-generated

Author: jiwonac

src/_includes/_foot.html

@@ -1,5 +1,5 @@
 <footer>
     <div>
-        <small>© Jiwon Chang 2026</small>
+        <small>© CC-BY Jiwon Chang 2026. All text and images are made by humans.</small>
     </div>
 </footer>