More support/guidance for coaches

[KimberleyCook]

• Collect more useful tips for coaches, Kriszta to ask in organsiers channel for more feedback
• Complete this infographic and link to it in the coach guide
• Shorter and longer version of the coach guide

[biggianteye]

A related, but more specific item: https://github.com/codebar/chapter-organiser-meetings/issues/24