Create a CONTRIBUTING.md

[ConnorNelson]

We want to specify the workflows for:

• Becoming a maintainer (PR against mantainers.yml)
• The process for decrypting encrypted data as a maintainer
• Creating a new module
  • git crypt init -k $MODULE
  • echo "**/tests_private/** filter=git-crypt-$MODULE diff=git-crypt-$MODULE" > ./challenges/$MODULE/.gitattributes
  • sed -n '/BEGIN PGP PUBLIC KEY BLOCK/,/END PGP PUBLIC KEY BLOCK/{p;/END PGP PUBLIC KEY BLOCK/q;}' ./maintainers.yml | gpg --import
    • This just imports the first key (which is root@pwn.college).
  • git crypt add-gpg-user --key-name "$MODULE" root@pwn.college
  • Additionally, maintainers.yml may need to be updated to make sure access continues to be allowed (otherwise you might create a new module, for which you aren't a maintainer, which sounds bad)

This all is untested, and probably should be wrapped by a cleaner interface. Probably one (or more) tools in ./tools/maintainers.