alreadyburnt aka eyedeekay via reddit.com: »A simple trick for customizing zzzot to host a filterable index of torrents being shared by i2psnark«. Link points to https://eyedeekay.github.io/zzzot-tracker-hack/
For the newcomers, eyedeekay is one of the main developers of Java I2P. Oh, and before you try the script, you might want to run shellcheck on it.