Adds hacktoberfest intro

Author: JJ

docs/Hacktoberfest.md

@@ -0,0 +1,13 @@
+# Hactkoberfest Squashaton
+
+The Perl 6 community celebrates a [monthly bug squash (long)
+day](https://github.com/rakudo/rakudo/wiki/Monthly-Bug-Squash-Day),
+and we make the one in Octobre coincide
+with [the Hacktoberfest](https://hacktoberfest.digitalocean.com/).
+
+We want all the community to benefit from this, so we have created a
+procedure that makes (relatively) easy to participate in the
+Squashathon, at the same time your pull-requesters participate in
+Hacktoberfest. The main objective of this is to be aware of the
+modules people have offered, so that the bots take care of them and
+publish modifications in the Perl 6 IRC channels.