Update footer.html

Author: abuttner

.github/pages/_includes/footer.html

@@ -10,7 +10,7 @@
       </div>
 
       <div style="text-align:center;">
-        <a href="https://www.mitre.org/"><img src="../assets/images/mitre-logo-blue-10.png" alt="MITRE Logo"></a><br>
+        <a href="https://www.mitre.org/"><img src="assets/images/mitre-logo-blue-10.png" alt="MITRE Logo"></a><br>
         <br>
       </div>