Add External Specification section (#1940)

Author: yezhizhen

index.html

@@ -11381,6 +11381,30 @@ <h3><dfn>Print Page</dfn></h3>
 </section> <!-- /Print Page -->
 </section> <!-- /Print -->
 
+<section class=informative>
+<h2>Appendices</h2>
+
+<section class=appendix>
+<h3>External Specifications</h3>
+<p class=note>
+The list is not exhaustive and might not be up to date.
+
+<p>The following external specifications define additional WebDriver modules:
+
+<ol>
+  <li><a href="https://html.spec.whatwg.org/multipage/system-state.html#user-agent-automation">Custom Scheme Handlers</a>
+  <li><a href="https://www.w3.org/TR/device-posture/#automation">Device Posture API</a>
+  <li><a href="https://www.w3.org/TR/fedcm/#automation">Federated Credential Management API</a>
+  <li><a href="https://www.w3.org/TR/gpc/#automation">Global Privacy Control</a>
+  <li><a href="https://www.w3.org/TR/permissions/#automation-webdriver">Permissions</a>
+  <li><a href="https://www.w3.org/TR/reporting-1/#automation">Reporting API</a>
+  <li><a href="https://privacycg.github.io/storage-access/#automation">Storage Access API</a>
+  <li><a href="https://www.w3.org/TR/webauthn-3/#sctn-automation">Web Authentication</a>
+</ol>
+
+</section>
+</section>
+
 
 <section class=appendix>
 <h2>Privacy</h2>