I can't find any documentation.

[nanastasov]

Can someone give me a documentation about this library?

[formula1]

Not sure if there's anything out there, maybe on the main site. For what it's worth, the examples are pretty straight forward.

Particles and create constraints between them

[forresto]

This was helpful for me: https://www.sitepoint.com/an-introduction-to-verlet-js/