Fix repo addresses

Author: david-christiansen

message-index/index.html

@@ -14,8 +14,8 @@ <h2>Welcome</h2>
 <p>
   So far, $messageCount$ errors and warnings are documented here.
   If you encounter a message that is not yet documented, please
-  <a href="https://github.com/haskell/error-messages/issues">open an issue</a> or
-  <a href="https://github.com/haskell/error-messages/pulls">submit a pull request with documentation</a>.
+  <a href="https://github.com/haskellfoundation/error-message-index/issues">open an issue</a> or
+  <a href="https://github.com/haskellfoundation/error-message-index/pulls">submit a pull request with documentation</a>.
   Pull requests with additional examples and improved explanations for
   existing messages are also very welcome.
 </p>