Review and update the entire meetup account

Now that our Meetup strategy is changing, some content might become outdated on our Meetup page. Most importantly, we have to discuss how the foundation should be referenced on any of our network pages. I've completed the most essential tasks so that we can send out the guidelines to volunteers asap. Please proceed with the remaining tasks and feel free to add others if needed:

- [x] Rename Meetup groups (remove the foundation from the group names)
- [x] Update group descriptions (changed the group names here as well)
- [ ] Update group descriptions (there is still reference to the foundation, this might have to be changed, might need a disclaimer)
- [ ] Review group and event cover images
- [ ] Review event names and descriptions
- [ ] Remove inactive groups if needed (more info were on this issue https://github.com/Green-Software-Foundation/meetup/issues/31)