New repo for top-level processing

[jklymak]

This is a new repo for things that are specific for cproof but that we want to share across processing scripts.

[jklymak]

@hvdosser this is where you can make PRs for Julias' changes to the website processing. Note you will still need to do on cproof

cd cproofutils
git fetch upstream
git checkout main. # optional.  
git reset --hard upstream/main

in order for any changes you make to take effect.