Fix HTML syntax error

index.html

@@ -113,7 +113,7 @@
                   <li>ALT-l: Focus on input bar</li>
                   <li>ALT-[0-9]: Focus on buffer</li>
                   <li>ALT-a: Focus on next buffer with activity</li>
-                  <li>ALT-<: Switch to previous buffer</li>
+                  <li>ALT-&lt;: Switch to previous buffer</li>
                   <li>ALT-g: Focus on buffer list filter</li>
                   <li>escape: disconnect</li>
                   <li>arrow keys: history navigation</li>