Fix readme.

Author: yxd-hde

README.rst

@@ -33,26 +33,28 @@ Run ``python-lambda-local -h`` to see the help.
 
     usage: python-lambda-local [-h] [-l LIBRARY_PATH] [-f HANDLER_FUNCTION]
                                [-t TIMEOUT] [-a ARN_STRING] [-v VERSION_NAME]
+                               [--version]
                                FILE EVENT
 
     Run AWS Lambda function written in Python on local machine.
 
     positional arguments:
-      FILE                  Lambda function file name
-      EVENT                 Event data file name.
+      FILE                  lambda function file name
+      EVENT                 event data file name
 
     optional arguments:
       -h, --help            show this help message and exit
       -l LIBRARY_PATH, --library LIBRARY_PATH
-                            Path of 3rd party libraries.
+                            path of 3rd party libraries
       -f HANDLER_FUNCTION, --function HANDLER_FUNCTION
-                            Lambda function handler name. Default: "handler".
+                            lambda function handler name, default: "handler"
       -t TIMEOUT, --timeout TIMEOUT
-                            Seconds until lambda function timeout. Default: 3
+                            seconds until lambda function timeout, default: 3
       -a ARN_STRING, --arn-string ARN_STRING
-                            arn string for function
+                            ARN string for lambda function
       -v VERSION_NAME, --version-name VERSION_NAME
-                            function version name
+                            lambda function version name
+      --version             print the version of python-lambda-local and exit
 
 Prepare development directory
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