Add dnsmichi events for Jul/Aug/Sep 2022: Kubernetes Community Days Berlin, Container Days, #EveryoneCanContribute cafe meetups

Why is this change being made?

Following the speaking process in https://about.gitlab.com/handbook/marketing/corporate-marketing/speaking-resources/#process for travel for Kubernetes Community Days Berlin. This MR also adds Container Days in September, and 2 #EveryoneCanContribute cafe meetups.

Author Checklist

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