Add documentation for trafikverket_train (#9333)

* Added documentation for trafikverket_train

* Removed data for image that was not relevant

* Added information about data that is retreived

* Removed redirect, added category sensors

* Clarified sensor values

* ✏️ Tweak

* Added information about missed weekday parameter

* Cleaned up examples

* Clarified examples for non required field

* Don't use !secret in example

Co-Authored-By: Klaas Schoute <klaas_schoute@hotmail.com>

* Fix typo

Co-Authored-By: Franck Nijhof <frenck@frenck.nl>

* Fix typo

Co-Authored-By: Franck Nijhof <frenck@frenck.nl>

* Fix typo

Co-Authored-By: Franck Nijhof <frenck@frenck.nl>

* Fix typo

Co-Authored-By: Franck Nijhof <frenck@frenck.nl>

* Fix typo

Co-Authored-By: Franck Nijhof <frenck@frenck.nl>

* Fix typo

Co-Authored-By: Franck Nijhof <frenck@frenck.nl>

* Fix typo

Co-Authored-By: Franck Nijhof <frenck@frenck.nl>

* Fix typo

Co-Authored-By: Franck Nijhof <frenck@frenck.nl>

* Fix typo

Co-Authored-By: Franck Nijhof <frenck@frenck.nl>

* ✏️ Fixed time to be optional

source/_components/trafikverket_train.markdown

@@ -0,0 +1,125 @@
+---
+layout: page
+title: "Trafikverket Train"
+description: "Instructions how to integrate Trafikverket Train within Home Assistant."
+date: 2019-04-27 16:32
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: trafikverket.png
+ha_category:
+  - Transport
+  - Sensor
+ha_release: 0.96
+ha_iot_class: Cloud Polling
+---
+
+Retrieve train departure information from [Trafikverket](https://www.trafikverket.se/).
+
+Use cases:
+
+- Retrieve the next departure and information connected to it for a specific train line.
+- Retrieve information for specific departure time on a specific train line.
+- Set up an alert or perform actions if your train is delayed or canceled.
+
+Data that is retrieved: 
+
+- Next departure for the specific train line.
+- Canceled status.
+- The number of minutes delayed.
+- Planned time if no delays occur.
+- Estimated time of arrival if delays occur.
+- Actual time - when it did arrive.
+- Other information / additional texts.
+- Deviations.
+
+## {% linkable_title Configuration %}
+
+To enable this sensor, use the following format in your `configuration.yaml`.
+
+```yaml
+sensor:
+   - platform: trafikverket_train
+     api_key: TRAFIKVERKET_API
+     trains:
+     - name: "Morning train to Malmö"
+       from: "Stockholm Central"
+       to: "Malmö C"
+       time: "9:25"
+       
+     - name: "Next train to Uppsala"
+       from: "Stockholm Central"
+       to: "Uppsala C"
+```
+
+{% configuration %}
+api_key:
+  description: Your personal API key from Trafikverket.
+  required: true
+  type: string
+trains:
+  description: Specify details on the departures to monitor.
+  required: true
+  type: map
+  keys:
+    name:
+      description: The name of the departure, will be the sensor name.
+      required: true
+      type: string
+    from:
+      description: The station from where the train departs.
+      required: true
+      type: string
+    to:
+      description: The destination station.
+      required: true
+      type: string
+    time:
+      description: Departure time to monitor, if not entered it will retrieve the next departure.
+      required: false
+      type: string
+    weekday:
+      description: Specify which days in the week to monitor the specific departure.
+      required: false
+      type: list
+      default: "[mon, tue, wed, thu, fri, sat, sun]"
+{% endconfiguration %}
+
+## {% linkable_title Obtaining API key %}
+
+Please click [here](https://api.trafikinfo.trafikverket.se/) and register to obtain the API key.
+
+## {% linkable_title Train station names %}
+
+Click [here](https://www.trafikverket.se/trafikinformation/tag/?ArrDep=departure&) to see an example of train station names.
+
+## {% linkable_title Examples %}
+
+```yaml
+sensor:
+- platform: trafikverket
+  api_key: !secret trafikverket_api_key
+  trains:
+  - name: "Train to work"
+    from: Sölvesborg
+    to: Kristianstad C
+    time: "07:28"
+    weekday: [mon, tue, wed, thu, fri]
+    
+  - name: "Train from work early"
+    from: Kristianstad C
+    to: Sölvesborg
+    time: "16:38"
+    
+  - name: "Train from work late"
+    from: Kristianstad C
+    to: Sölvesborg
+    time: "17:02"
+    weekday: [sat, sun]
+    
+  - name: "Next train to Uppsala"
+    from: "Stockholm Central"
+    to: "Uppsala C"
+    
+```