Supla component docs (#8971)

* Supla component docs

* Update supla.markdown

source/_components/supla.markdown

@@ -0,0 +1,53 @@
+---
+layout: page
+title: "Supla"
+description: "Instructions for integration with Supla Cloud's Web API"
+date: 2019-03-14 20:05
+sidebar: true
+comments: true
+sharing: true
+footer: true
+logo: supla.png
+ha_release: 0.92
+ha_category:
+  - Hub
+  - Cover
+ha_iot_class: Cloud Polling
+redirect_from:
+  - /components/cover.supla/
+---
+
+The [Supla](http://supla.org) is an Open Source home automation system for ESP8266 based devices. It has its own set of protocols, it's own firmware and commercially available devices (produced for example by [Zamel](https://supla.zamel.pl/))
+
+Currently only covers (shutters in Supla's lingo) are supported, but, thanks to comprehensive and universal REST API, it's pretty easy to add more.
+
+Right now it's impossible to add single devices -- all of them are discovered from
+Supla Cloud's servers.
+
+## {% linkable_title Configuration %}
+
+To use Supla devices in your installation, add the following to your `configuration.yaml`:
+
+```yaml
+supla:
+    servers:
+        - server: svr1.supla.org
+          access_token: your_really_long_access_token
+```
+
+{% configuration %}
+servers:
+  description: List of server configurations.
+  requires: true
+  type: list
+server:
+  description: Address of your Supla Cloud server (either IP or DNS name)
+  required: true
+  type: string
+access_token:
+  description:
+    An access token for REST API configuration. Can be acquired from
+    http[s]://your.server.org/integrations/tokens (please add at least Channel's Read and Action Execution permissions).
+  required: true
+  type: string
+{% endconfiguration %}