Add manual alarm doc

source/components/alarm_control_panel.manual.markdown

@@ -0,0 +1,31 @@
+---
+layout: page
+title: "Manual alarm support"
+description: "Instructions how to integrate manual alarms into Home Assistant."
+date: 2015-10-13 19:10
+sidebar: false
+comments: false
+sharing: true
+footer: true
+---
+
+<img src='/images/supported_brands/preferences-system-privacy.png' class='brand pull-right' />
+This platform enables you to set manual alarms in Home Assistant.
+
+```yaml
+# Example configuration.yaml entry
+alarm_control_panel:
+  platform: manual
+  name: "HA Alarm"
+  code: PASSCODE
+  pending_time: 60
+  trigger_time: 120
+```
+
+Configuration variables:
+
+- **name** (*Optional*): The name of the alarm. Default is 'HA Alarm'.
+- **code** (*Optional*): If defined, specifies a code to enable or disable the alarm in the frontend.
+- **pending_time** (*Optional*): The time in seconds of the pending time before arming the alarm. Default is 60 seconds.
+- **trigger_time** (*Optional*): The time in seconds of the trigger time in which the alarm is firing. Default is 120 seconds.
+