Added yandex tts doc (#1775)

source/_components/tts.yandextts.markdown

@@ -0,0 +1,46 @@
+---
+layout: page
+title: "Yandex TTS"
+description: "Instructions how to setup Yandex SpeechKit TTS with Home Assistant."
+date: 2017-01-05 03:04
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: yandex.png
+ha_category: Text-to-speech
+ha_release: 0.36
+---
+
+The `yandextts` text-to-speech platform uses [Yandex SpeechKit](https://tech.yandex.com/speechkit/) Text-to-Speech engine to read a text with natural sounding voices.
+
+To enable text-to-speech with Yandex SpeechKit, add the following lines to your `configuration.yaml`:
+
+```yaml
+# Example configuration.yaml entry
+tts:
+  - platform: yandextts
+    api_key: 'XXXXXXXX'
+```
+
+Configuration variables:
+
+- **api_key** (*Requered*): API Key for use this service. 
+- **language** (*Optional*): The language to use. Defaults to `en-us`. Supported en-EN, ru-RU, uk-UK, tr-TR
+- **codec** (*Optional*): Audo codec. Default is 'mp3'. Supported us mp3, wav, opus.
+- **voice** (*Optional*): Speaker voice. Default is 'zahar'. Supported female voices are jane, oksana, alyss, omazh and male voices are zahar and ermil
+
+
+See on api [documentation](https://tech.yandex.com/speechkit/cloud/doc/dg/concepts/speechkit-dg-tts-docpage/) for details. N.B. english version of documentation is outdated. So you could receive api key [here](https://developer.tech.yandex.ru/)
+
+A full configuration sample:
+
+```yaml
+# Example configuration.yaml entry
+tts:
+  - platform: yandextts
+    api_key: 'XXXXX'
+    language: 'ru-RU'
+    codec: mp3
+    voice: oksana
+```