doc(readme): community section (#392)

* doc(readme): community section

Adds a community section, to mention communication channels and the
community call.

* fix: remove dead section

* fix: improve wording

README.md

@@ -57,6 +57,34 @@ To get started, [install Tanka](https://tanka.dev/install) first, and then
 [follow the tutorial](https://tanka.dev/tutorial/overview). This should get you
 on track quickly.
 
+## :busts_in_silhouette: Community
+
+There are several places to connect with the Tanka community:
+
+- `#tanka` on [Grafana Slack](https://grafana.slack.com)
+- Mailing lists
+  - [`tanka-announce`](https://groups.google.com/forum/#!forum/tanka-announce):
+    Low frequency list with announcements, releases, etc
+  - [`tanka-users`](https://groups.google.com/forum/#!forum/tanka-users):
+    General purpose group for discussions, community support and more
+
+Please don't ask individual project members or open GitHub issues for support
+requests. Use one of the above channels so everyone in the community can
+participate.
+
+---
+
+[![Community
+Call](./docs/img/community-call.png)](https://docs.google.com/document/d/1mEsc0GxlnwbWAXzbIP7tBb6T5WgAI66_0gIWJzqB93o/edit)
+
+Grafana Labs hosts a monthly community call for the Tanka project. Notes and the
+meeting URL can be found in a [Google
+Doc](https://docs.google.com/document/d/1mEsc0GxlnwbWAXzbIP7tBb6T5WgAI66_0gIWJzqB93o/edit).  
+Join us to share why you love Tanka, why you have a hard time, tell us what you
+would like to see improved and hear about latest news!
+
+Furthermore, see [`LICENSE`](./LICENSE) and [`GOVERNANCE`](./GOVERNANCE.md).
+
 ## :book: Additional resources
 
 - https://jsonnet.org/, the official Jsonnet documentation provides lots of