move coreos-cloudinit into config/cloudinit

Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au>

config/cloudinit/Documentation/cloud-config-oem.md

@@ -0,0 +1,37 @@
+## OEM configuration
+
+The `coreos.oem.*` parameters follow the [os-release spec][os-release], but have been repurposed as a way for coreos-cloudinit to know about the OEM partition on this machine. Customizing this section is only needed when generating a new OEM of CoreOS from the SDK. The fields include:
+
+- **id**: Lowercase string identifying the OEM
+- **name**: Human-friendly string representing the OEM
+- **version-id**: Lowercase string identifying the version of the OEM
+- **home-url**: Link to the homepage of the provider or OEM
+- **bug-report-url**: Link to a place to file bug reports about this OEM
+
+coreos-cloudinit renders these fields to `/etc/oem-release`.
+If no **id** field is provided, coreos-cloudinit will ignore this section.
+
+For example, the following cloud-config document...
+
+```yaml
+#cloud-config
+coreos:
+  oem:
+    id: "rackspace"
+    name: "Rackspace Cloud Servers"
+    version-id: "168.0.0"
+    home-url: "https://www.rackspace.com/cloud/servers/"
+    bug-report-url: "https://github.com/coreos/coreos-overlay"
+```
+
+...would be rendered to the following `/etc/oem-release`:
+
+```yaml
+ID=rackspace
+NAME="Rackspace Cloud Servers"
+VERSION_ID=168.0.0
+HOME_URL="https://www.rackspace.com/cloud/servers/"
+BUG_REPORT_URL="https://github.com/coreos/coreos-overlay"
+```
+
+[os-release]: http://www.freedesktop.org/software/systemd/man/os-release.html