Merge pull request AOMediaCodec#340 from louquillio/modify-html-legend

Modify html legend

Author: louquillio

00.html-legend.md

@@ -5,6 +5,6 @@
 
 This is an internal AOMedia working document and **not an approved version** of
 the AV1 specification. The approved AV1 bitstream specification can be found
-here: <https://aomediacodec.github.io/av1-spec/av1-spec.pdf>
+here: <https://github.com/AOMediaCodec/av1-spec/releases>
 
 </div>