Ping example using js-libp2p

Based on https://docs.libp2p.io/tutorials/getting-started/javascript/ with some improvements. ;)

npm install

node main.js

Copy the address from the output.

In a separate console

node main.js <address>

The second node will ping the first one and print the latency.

Hint: you can run it also against go-libp2p-ping