Unify the extension

[carletex]

We agreed (with @damianmarti) that having the same extension for both seasons is the way to go

Let's update https://github.com/BuidlGuidl/ctf.buidlguidl.com/tree/extension with the new stuff from the extension from argentina (+ Update README). We can add the Devconnect argentina contracts addresses for now, and we can update whenever we deploy the final version.