Update the status of the website in the README

So we still haven't discussed what's going to happen to
www.jool.mx, but at least we can fix this little README lie.

"Progress" on #190.

README.md

@@ -7,7 +7,7 @@ An [SIIT and a NAT64](https://www.jool.mx/en/intro-xlat.html) for Linux.
 > Jool's website is hosted in two separate domains simultaneously:
 > 
 > - https://www.jool.mx
-> - https://nicmx.github.io/Jool (not available from IPv6.)
+> - https://nicmx.github.io/Jool
 
 ## Documentation