style(3p/nix): Rename the project to tvix r/1317

Changes the derivation name & README overview to say "Tvix" instead of
"tazjix".

The previous name was mostly intended as a joke, and a way for me to
distinguish output paths. It's certainly not the intention to have a
portmanteau with my name here, especially now that several people are
contributing to the fork.

Change-Id: Icface5484d52355111eca23b2f6bd3b9e5567275
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1212
Reviewed-by: glittershark <grfn@gws.fyi>
Tested-by: BuildkiteCI

0 files changed, 0 insertions, 0 deletions