Remove freenode references

[skeet70]

Introduction

Seems like since the freenode explosion there is no longer a #bookshelf on freenode. I didn't find that out until after I created an account on irc.com, I would've rather known it ahead of time.

Issue Description

freenode.net#bookshelf doesn't really exist anymore. References to it in documentation for bookshelf and knex should be removed. If a satisfying alternative exists (liberia? zulip? discord?), references could be replaced with that.

Steps to reproduce issue

Connect to freenode.net, have to register with irc.com, connect to #bookshelf, see it's unclaimed/unused.

Expected behaviour

A community of people helping each other with bookshelf and knex issues.

Actual behaviour

🦗

[brazc]

Agreed, joined the channel and it's just me.

Perhaps for the time being it would be possible to organize an unofficial discord server?