More tweaks to developer docs

source/developers/component_initialization.markdown

@@ -0,0 +1,36 @@
+---
+layout: page
+title: "Initializing your components"
+description: "Instructions how to handle initialization of your component."
+date: 2016-04-16 13:32
+sidebar: true
+comments: false
+sharing: true
+footer: true
+---
+
+After loading, the bootstrapper will call `setup(hass, config)` method on the component to initialize it.
+
+### {% linkable_title hass: the Home Assistant instance %}
+
+The Home Assistant instance contains three objects to help you interact with the system.
+
+| Object | Description |
+| ------ | ----------- |
+| `hass.config` | This is the core configuration of Home Assistant exposing location, temperature preferences and config directory path. [Details](https://github.com/home-assistant/home-assistant/blob/dev/homeassistant/core.py#L687)
+| `hass.states` | This is the StateMachine. It allows you to set states and track when they are changed. [See available methods](https://github.com/home-assistant/home-assistant/blob/dev/homeassistant/core.py#L434). |
+| `hass.bus` | This is the EventBus. It allows you to trigger and listen for events.<br>[See available methods](https://github.com/home-assistant/home-assistant/blob/dev/homeassistant/core.py#L229). |
+| `hass.services` | This is the ServiceRegistry. It allows you to register services.<br>[See available methods](https://github.com/home-assistant/home-assistant/blob/dev/homeassistant/core.py#L568). |
+
+### {% linkable_title config: User given configuration. %}
+
+The `config` parameter is a dictionary containing the user supplied configuration. The keys of the dictionary are the component names and the value is another dictionary with the component configuration.
+
+If your configuration file contains the following lines:
+
+```yaml
+example:
+  host: paulusschoutsen.nl
+```
+
+Then in the setup method of your component you will be able to refer to `config['example']['host']` to get the value `paulusschoutsen.nl`.