Add a reference to XVim2 in XVim

[snipem]

I was searching in the issues and googled "XVim2" afterwards only to end up in the neighboring project.

Thanks!

[qubitz]

Please do, Google results are not pulling up the XVim2 repo. I had been poking my head in every now and then to the XVim repo for a few months only to find XVim2 just now.