You can verify any contribution by downloading the required files and using a command line instruction to run the verification
npm install -g snarkjs@0.6.11
then
snarkjs zkv [.r1cs] [.ptau] [.zkey]
or
snarkjs zkvi [cxx_0000.zkey] [.ptau] [.zkey]
A successful verification will end with:
[INFO] snarkJS: ZKey Ok!