Add incomplete ADOPTERS file

Please add your use cases here. There are many adopters that I know about but have not
documented here, please fill this in.

I divided this into production users, and also linked a selection of open source projects
that I know about here.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

ADOPTERS.md

@@ -0,0 +1,17 @@
+## LinuxKit Adopters
+
+_This list is currently under construction. Please add your use cases to this with a PR. Thanks!_
+
+# Production Users
+
+**_[Docker Desktop](https://www.docker.com/products/docker-desktop)_** - Docker Desktop for Mac and Windows uses LinuxKit to provide an embedded, invisible virtual machine in order to run Linux containers and to run Kubernetes. There are currently millions of active users.
+
+# Projects Using LinuxKit
+
+**_[LinuxKit Nix](https://github.com/nix-community/linuxkit-nix)_** aims to provide a Linux Nix VM for macOS.
+
+**_[cfdev](https://github.com/cloudfoundry-incubator/cfdev)_** A fast and easy local Cloud Foundry experience on native hypervisors, powered by LinuxKit with VPNKit
+
+**_[dm-linuxkit](https://github.com/dotmesh-io/dm-linuxkit)_** A dotmesh controller for LinuxKit persistent storage management.
+
+**_[Zenbuild](https://github.com/zededa/zenbuild)_** Linuxkit based IoT Edge Operating System (Zenix)

README.md

@@ -21,10 +21,10 @@ LinuxKit currently supports the `x86_64`, `arm64`, and `s390x` architectures on
 
 - [LinuxKit kubernetes](https://github.com/linuxkit/kubernetes) aims to build minimal and immutable Kubernetes images. (previously `projects/kubernetes` in this repository).
 - [LinuxKit LCOW](https://github.com/linuxkit/lcow) LinuxKit images and utilities for Microsoft's Linux Containers on Windows.
-- [LinuxKit Nix](https://github.com/nix-community/linuxkit-nix) aims to provide a Linux Nix VM for macOS.
 - [linux](https://github.com/linuxkit/linux) A copy of the Linux stable tree with branches LinuxKit kernels.
 - [virtsock](https://github.com/linuxkit/virtsock) A `go` library and test utilities for `virtio` and Hyper-V sockets.
 - [rtf](https://github.com/linuxkit/rtf) A regression test framework used for the LinuxKit CI tests (and other projects).
+- [homebrew](https://github.com/linuxkit/homebrew-linuxkit) Homebrew packages for the `linuxkit` tool.
 
 ## Getting Started
 
@@ -157,6 +157,10 @@ This is an open project without fixed judgements, open to the community to set t
 
 There are weekly [development reports](reports/) summarizing work carried out in the week.
 
+## Adopters
+
+We maintain an incomplete list of [adopters](adopters.md). Please open a PR if you are using LinuxKit in production or in your project, or both.
+
 ## FAQ
 
 See [FAQ](docs/faq.md).