Port edward egg to CS6, change URL for CS5 index

Hello there!

First of, congratulations on the CS6 release! I am the author of the
edward egg, going forward I would only like to release new versions for
CS6. Would it therefore be possible to update the CS5 .release-info URL
for the edward egg to:

	https://raw.githubusercontent.com/nmeum/edward/refs/heads/release/chicken-5/edward.release-info

As soon as that is done, I would tag a new CS6-only release. If
convenient, the following .release-info file could thus already
be added to the CS6 index:

	https://raw.githubusercontent.com/nmeum/edward/refs/heads/master/edward.release-info

Note though that I haven't released a CS6-compatible version yet
to not break the CS5 index. I will do so as soon the egg index
is updated as requested :)

Cheers,
Sören