Add sample doc for elgato light service (#63)

* Add sample doc for elgato light service

Adds sample documentation for elgato light service (codeoverflow-org/nodecg-io#247).

* Update elgato-light sample doc to adhere to new template

Author: hlxid

docs/samples/elgato-light.md

@@ -0,0 +1,44 @@
+## Using the elgato-light sample bundle
+
+The elgato-light example bundle in `samples/elgato-light` demonstrates the ability to controll elgato keylights and elgato lightstrips. Here is a guide to how to get it working.
+
+### Prerequisites
+
+You will need a working `nodecg-io` installation. If you have non yet take a
+look at [installation guide](../getting_started/install.md). You may need to
+install this bundle, so take a look at the
+[“Try an included sample”](../getting_started/try_example_bundle.md)-Guide. It
+will also tell you how to log in and how to use the GUI.
+
+**You also need:**
+
+-   at least one elgato keylight or lightstrip
+
+### Configure the elgato-light sample bundle
+
+1. In NodeCG, create a new elgato-light service instance.
+2. Enter your IP address of your light and the type (`KeyLight` or `LightStrip`):
+
+    ```json
+    {
+        "lights": [
+            {
+                "ipAddress": "xxx.xxx.xxx.xxx",
+                "lightType": "KeyLight",
+                "name": "MyLight1"
+            }
+        ]
+    }
+    ```
+
+    You can add as many lights to this service as you wish by adding more objects inside the `lights` array.
+
+    `name` is optional and can be used to identify lights in bundles. You can omit it if you don't use the name to get it in any bundle.
+
+    After entering it, click save.
+
+3. Set the sample's (`elgato-light`) dependency to be the newly created
+   service instance (of type `elgato-light`).
+4. Check the NodeCG logs:
+
+    Your lights should blink for three seconds and you should see the current brightness in the NodeCG logs.

mkdocs.yml

@@ -64,6 +64,7 @@ nav:
           - Discord:
                 - Discord API sample: samples/discord.md
                 - Discord RPC sample: samples/discord-rpc.md
+          - Elgato Light sample: samples/elgato-light.md
           - GitHub sample: samples/github.md
           - Googleapis:
                 - GSheets sample: samples/gsheets.md