Update Projects page - remove OTS core event

[gsambrotta]

Need to update the project pages with all the OTS 'sister' projects and remove all core OTS events.

1. Remove:

• Workshops
• Learners Meetups
• Continuos Learning Groups

1. Check if we got new projects and add them
2. OTS Conf ?
3. School of Machines, Making & Make-Believe (http://schoolofma.org/programs/)

[lehmannro]

I think the very purpose of this was showing the different formats of OpenTechSchool. IMHO all sister projects (Hackership, OTSconf, School of Ma) should go on some other page.

Workshops could arguably be removed since every chapter does them (I have something for that in the upcoming Jekyll collections rewrite.)

I don't know of any other new projects.

OTSconf could also be featured with some kind of banner for the time being.