The java.net.http/java.net.http package description specifies 3 RFCs to which the implemented protocols (HTTP/1.1, HTTP/2, and WebSocket) conform to.
This is done using direct HTML hyper text references.

We should add some `@spec` corresponding to these at the end of the package description. Something like:

 * @spec https://www.rfc-editor.org/info/rfc7540
 * RFC 7540: Hypertext Transfer Protocol Version 2 (HTTP/2)
 * @spec https://www.rfc-editor.org/info/rfc2616
 * RFC 2616: Hypertext Transfer Protocol (HTTP/1.1)
 * @spec https://www.rfc-editor.org/info/rfc6455
 * RFC 6455: The WebSocket Protocol
 
In addition we should evaluate the opportunity of referencing newer RFCs, since all of these have been obsoleted. This would require figuring out whether we still conform to the newer RFC though.

An other update would be to replace links to https://tools.ietf.org/ with corresponding links to https://www.rfc-editor.org/