I got an invitation to participate in something called hactoberfest?

It is on the link: https://hacktoberfest.digitalocean.com

It looks like fun, and a way to draw attention to open source software development. 

If Pharo (and its sub-projects) is not part of it, this link says how to participate: 
https://hacktoberfest.digitalocean.com/resources

Best,

Kasper