Updated messagebird comment to show how to get a key
# enable/disable sending messagebird SMS
SEND_MESSAGEBIRD="YES"
+# to get an access key, create a free account at https://www.messagebird.com
+# verify and activate the account (no CC info needed)
+# login to your account and enter your phonenumber to get some free credits
+# to get the API key, click on 'API' in the sidebar, then 'API Access (REST)'
+# click 'Add access key' and fill in data (you want a live key to send SMS)
+
# Without an access key, netdata cannot send Messagebird text messages.
MESSAGEBIRD_ACCESS_KEY=""
MESSAGEBIRD_NUMBER=""