Merge pull request #1493 from srenatus/sr/adopters

ADOPTERS: replace Documentation/production-users.md, add Chef

ADOPTERS.md

+# Adopters
+
+This is a list of production adopters of Dex (in alphabetical order):
+
+- [Banzai Cloud](https://banzaicloud.com) is using Dex for authenticating to its Pipeline control plane and also to authenticate users against provisioned Kubernetes clusters (via Kubernetes OIDC support).
+- [Chef](https://chef.io) uses Dex for authenticating users in [Chef Automate](https://automate.chef.io/). The code is Open Source, available at [`github.com/chef/automate`](https://github.com/chef/automate).
+- [Pusher](https://pusher.com) uses Dex for authenticating users across their Kubernetes infrastructure (using Kubernetes OIDC support) in conjunction with the [OAuth2 Proxy](https://github.com/pusher/oauth2_proxy) for protecting web UIs.

Documentation/production-users.md

-# Production users
-
-This document tracks people and use cases for dex in production. [Join the community](https://github.com/dexidp/dex/), and help us keep the list up-to-date.
-
-- [Banzai Cloud](https://banzaicloud.com) is using dex for authenticating to its Pipeline control plane and also to authenticate users against provisioned Kubernetes clusters (via Kubernetes OIDC support).