Update acknowledgements (#552)

Updates acknowledgements with the source of Ed25519 and X25519 as well
as individuals who contributed fixes and features either here or in
webcrypto-secure-curves.

Author: panva

spec/Overview.html

@@ -15768,6 +15768,27 @@ <h2>Acknowledgments</h2>
           method in the {{Crypto}} interface was originally proposed by Adam Barth to the
           <a href="https://wiki.whatwg.org/wiki/Crypto">WHATWG</a>.
         </p>
+        <p>
+          Ed25519 and X25519 were originally specified in the
+          <a href="https://wicg.github.io/webcrypto-secure-curves/">Secure Curves in the Web Cryptography API</a>
+          specification at the WICG.
+        </p>
+        <p>
+          Thanks to
+          Ben Wiederhake,
+          Divy Srivastava,
+          Dominique Hazael-Massieux,
+          Filip Skokan,
+          Kagami Sascha Rosylight,
+          Luca Casonato,
+          Martin Thomson,
+          Philippe Le Hégaret,
+          Tobias Nießen,
+          and Anna Weine
+          for their contributions and improvements made to this specification
+          and the <a href="https://github.com/WICG/webcrypto-secure-curves/">Secure Curves in the Web Cryptography API</a>
+          specification.
+        </p>
       </section>
     </section>