add doc & etc..

Author: aofdev

README.md

@@ -6,6 +6,21 @@
   <img src ="https://i.imgur.com/HD07Rj9.gif" />
 </p>
 
+## Authentication
+1. Visit the [Google Developers Console](https://console.developers.google.com/project)
+2. Create a new project or click on an existing project.
+3. Navigate to  **APIs & auth** > **APIs section** and turn on the following APIs (you may need to enable billing in order to use these services): Google Cloud Speech API
+4. Navigate to **APIs & auth** >  **Credentials** and then:
+  * If you want to use a new service account key, click on **Create credentials** and select **Service account key**. After the account key is created, you will be prompted to download the JSON key file that the library uses to authenticate your requests.
+  * If you want to generate a new service account key for an existing service account, click on **Generate new JSON key** and download the JSON key file.
+
+## Config
+After at Authentication done getting the json file and insert At ``app.js``
+``` bash
+const speech = Speech({
+   keyFilename: '' // insert this file json here.
+});
+```
 
 ## Setup Project