Update readme

README.MD

@@ -28,24 +28,58 @@ On Windows download [binary](https://github.com/mercury2269/sqsmover/releases).
 After downloading, rename binary file 'sqsmover.exe', then add to PATH.
 
 ## Configuring Credentials
-Before using the sqsmover ensure that you've configured credentials. The best
-way to configure credentials on a development machine is to use the
-`~/.aws/credentials` file, which might look like:
+Before using the sqsmover ensure that you've configured AWS credentials. The best
+way to configure credentials on a development machine is to create the credentials file
+`~/.aws/credentials`, which might look like:
 
 ```
 [default]
-aws_access_key_id = AKID1234567890
-aws_secret_access_key = MY-SECRET-KEY
+aws_access_key_id = <YOUR_ACCESS_KEY_ID>
+aws_secret_access_key = <YOUR_SECRET_ACCESS_KEY>
+```
+
+As an alternative you can set AWS credentials in the environment variables.
+
+The following examples show how you configure the environment variables.
+
+Linux, OS X, or Unix
+
+```
+export AWS_ACCESS_KEY_ID=YOUR_AKID
+export AWS_SECRET_ACCESS_KEY=YOUR_SECRET_KEY
+```
+Windows
+
+```
+set AWS_ACCESS_KEY_ID=YOUR_AKID
+set AWS_SECRET_ACCESS_KEY=YOUR_SECRET_KEY
 ```
 
 ## Usage
 
-Supply the queue source and destination names as parameters as follows
-Region will default to us-west-2, you can also override it with -region flag
+```
+sqsmover --help
+
+usage: sqsmover.exe --source=SOURCE --destination=DESTINATION [<flags>]
+
+Flags:
+      --help                     Show context-sensitive help (also try
+                                 --help-long and --help-man).
+  -s, --source=SOURCE            Source queue to move messages from
+  -d, --destination=DESTINATION  Destination queue to move messages to
+  -r, --region="us-west-2"       AWS Region for source and destination queues
+```
+
+Examples:
+
+Region will default to `us-west-2`, you can also override it with `--region` flag
 
 ```
 sqsmover --source=my_source_queue_name --destination=my_destination_queuename
 sqsmover --source=my_source_queue_name --destination=my_destination_queuename --region=eu-west-1
+
+-- shorthand
+sqsmover -s my_source_queue_name -d my_destination_queuename -r eu-west-1
 ```