adding documentation for the yandex_transport component (#10375)

* adding documentation for the yandex_transport component
https://github.com/home-assistant/home-assistant/pull/26252#discussion_r321543743

* fixing comments, add some configuration information

* removing redirect_from section

* ✏️ Tweak

* fixed information about the tracking of the specific routes

* ✏️ Tweaks

source/_components/yandex_transport.markdown

@@ -0,0 +1,84 @@
+---
+title: "Yandex transport"
+description: "Instructions on how to set up Yandex transport with Home Assistant."
+logo: yandex.png
+ha_category:
+  - Sensor
+  - Transport
+ha_release: "0.100"
+---
+
+The `yandex_tranport` sensor platform uses [Yandex Maps](https://maps.yandex.ru/) it will give you the time until the next departure time from a bus/tramway/etc stop.
+
+The [Yandex Maps](https://maps.yandex.ru/) website can help to determine the id of your bus stop. You can select a bus stop by clicking on the map, and look to the URL:
+
+`https://yandex.ru/maps/213/moscow/?ll=37.722565%2C55.806662&masstransit%5BstopId%5D=stop__9642962&mode=masstransit&z=16.52`
+
+Where stop id is: **9642962**
+
+If you want to track only specific routes, you can add them in the routes section.
+
+## Configuration
+
+To activate Yandex Transport, add the following lines to your `configuration.yaml`:
+
+```yaml
+# Example configuration.yaml entry
+sensor:
+  - platform: yandex_tranport
+    stop_id: YOUR_STOP_ID
+```
+
+{% configuration %}
+stop_id:
+  description: The ID of the transport stop to get the information for.
+  required: true
+  type: string
+routes:
+  description: "A list of a specific bus, tramway, etc routes at the stop. This is the same as the bus number, e.g., `83`. If the routes with letters contain Cyrillic symbols, so write them to `configuration.yaml` in Cyrillic."
+  required: false
+  type: list
+name:
+  description: A friendly name for this sensor.
+  required: false
+  default: Yandex Transport
+  type: string
+{% endconfiguration %}
+
+## Full configuration example
+
+The configuration sample below shows how an entry can look like:
+
+```yaml
+# Example configuration.yaml entry
+sensor:
+  - platform: yandex_transport
+    name: Bus_to_subway
+    stop_id: 9639579
+    routes:
+      - 63
+      - 179
+      - 179к
+      - 154
+      - 591
+      - 677к
+```
+
+## Options For Entities
+
+You can configure view information about the next bus using Lovelace card.
+To enable displaying the relative time in your `default_vew` add the following lines:
+
+```yaml
+# Example default_view entry
+title: Home Assistant
+views:
+    cards:
+      - entities:
+          - entity: sensor.yandex_transport
+            format: relative
+        type: entities
+    path: default_view
+```
+
+Data provided by https://maps.yandex.ru