Updated .env.example file to elaborate of the proper usage for IAM AP…

…I keys and credentials and added URL parameters

examples/.env.example

@@ -1,6 +1,20 @@
-SPEECH_TO_TEXT_IAM_APIKEY=""
-SPEECH_TO_TEXT_USERNAME=""
-SPEECH_TO_TEXT_PASSWORD=""
-TEXT_TO_SPEECH_IAM_APIKEY=""
-TEXT_TO_SPEECH_USERNAME=""
-TEXT_TO_SPEECH_PASSWORD=""
+# Replace this if you are using a region specific service
+SPEECH_TO_TEXT_URL=https://stream.watsonplatform.net/speech-to-text/api
+
+# If your using IAM API keys use this and do not input credentials:
+SPEECH_TO_TEXT_IAM_APIKEY=<Your API key>
+
+# If your Speech to Text credentials contain username and password use the following:
+SPEECH_TO_TEXT_USERNAME=
+SPEECH_TO_TEXT_PASSWORD=
+
+# Replace this if you are using a region specific service
+TEXT_TO_SPEECH_URL=https://stream.watsonplatform.net/text-to-speech/api
+
+# If your using IAM API keys use this and do not input credentials:
+TEXT_TO_SPEECH_IAM_APIKEY=<Your API key>
+
+# If your Text to Speech credentials contain username and password use the following:
+TEXT_TO_SPEECH_USERNAME=
+TEXT_TO_SPEECH_PASSWORD=
+