README.md in cellular-2.0.0 vs README.md in cellular-2.1.0

@@ -34,11 +34,11 @@
 
 ```ruby
 Cellular.configure do |config|
   config.username = 'username'
   config.password = 'password'
-  config.backend  = Cellular::Backends::Sendega
+  config.backend = Cellular::Backends::Sendega
   config.sender = 'Default custom sender'
   config.country_code = 'NO'
 end
 ```
 
@@ -46,24 +46,25 @@
 interface to interact with queue backends. Read appropriate documentation to set up queue.
 
 
 ### Available Backends
 
-* [CoolSMS](http://coolsms.com/)
-* [Sendega](http://sendega.com/)
+* [Cellular::Backends::CoolSMS](http://coolsms.com/)
+* [Cellular::Backends::Sendega](http://sendega.com/)
+* [Cellular::Backends::Twilio](http://twilio.com/)
 * Log (logs to `$stdout`)
 * Test (adds messages to `Cellular.deliveries`)
 
 
 ### Sending SMSs
 
 The options supported may differ between backends.
 
 ```ruby
 sms = Cellular::SMS.new(
-  recipient: '47xxxxxxxx',
-  sender: 'Custom sender',
+  recipient: '+47xxxxxxxx', # Valid international format
+  sender: '+370xxxxxxxx',
   message: 'This is an SMS message',
   price: 0,
   country_code: 'NO' # defaults to Cellular.config.country_code
 )
 
@@ -71,12 +72,12 @@
 ```
 For use with multiple recipients in one request use:
 
 ```ruby
 sms = Cellular::SMS.new(
-  recipients: ['47xxxxxxx1','47xxxxxxx2','47xxxxxxx3'],
-  sender: 'Custom sender',
+  recipients: ['+47xxxxxxx1','+47xxxxxxx2','+47xxxxxxx3'],
+  sender: '+370xxxxxxxx',
   message: 'This is an SMS message',
   price: 0,
   country_code: 'NO' # defaults to Cellular.config.country_code
 )
 
@@ -90,12 +91,12 @@
 and are concerned that it might time out or something. To use it, just call
 `deliver_async` instead of `deliver` on the SMS object:
 
 ```ruby
 sms = Cellular::SMS.new(
-  recipient: '47xxxxxxxx',
-  sender: 'Custom sender',
+  recipient: '+47xxxxxxxx',
+  sender: '+47xxxxxxxx',
   message: 'This is an SMS message'
 )
 
 sms.deliver_async
 ```
@@ -111,24 +112,33 @@
 Using ActiveJob, Cellular allows you to schedule the time when an SMS will be sent.
 Just call `deliver_async(wait_until: timestamp)` or `deliver_async(wait: time)` on the SMS object:
 
 ```ruby
 sms = Cellular::SMS.new(
-  recipient: '47xxxxxxxx',
-  sender: 'Custom sender',
+  recipient: '+47xxxxxxxx',
+  sender: '+47xxxxxxxx',
   message: 'This is an SMS message'
 )
 
 sms.deliver_async(wait_until: Date.tomorrow.noon)
 ```
 
+## Troubleshooting
+
+If you are using Twilio as a backend, please make sure you add or (port)[https://www.twilio.com/help/faq/porting] a phone number to your account so, that you can use that as a sender option. You won't be able to send messages from any phone number unless you port it to Twilio. 
+
+Also, make sure phone numbers are in valid international format: 
+[`+47xxxxxx`, `+370xxxxx`]
+
 ## Contributing
 
 1. Fork it
-2. Create your feature branch (`git checkout -b my-new-feature`)
-3. Commit your changes (`git commit -am 'Add some feature'`)
-4. Push to the branch (`git push origin my-new-feature`)
-5. Create pull request
+2. Create your feature branch (`git checkout -b feature/my-new-feature`)
+3. Write your code and necessary tests 
+4. Run your tests (`bundle exec rspec`)
+5. Commit your changes (`git commit -am 'Add some feature'`)
+6. Push to the branch (`git push origin feature/my-new-feature`)
+7. Create pull request and be awesome!
 
 
 ## Credits
 
 Hyper made this. We're a digital communications agency with a passion for good code,