Update the README

README.md

@@ -22,22 +22,22 @@ Note that the command line tool is spelled `cfn-flip` with a hyphen, while the p
 
 ### Command line tool
 
-    cfn-flip [-h] [-c] [input] [output]
-
-    AWS CloudFormation Template Flip is a tool that converts AWS CloudFormation
-    templates between JSON and YAML formats, making use of the YAML format's short
-    function syntax where possible.
-
-    positional arguments:
-      input        File to read from. If you do not supply a file, input will be
-                   read from stdin.
-      output       File to write to. If you do not supply a file, output will be
-                   written to stdout.
-
-    optional arguments:
-      -h, --help   show this help message and exit
-      -c, --clean  Performs some opinionated cleanup on your template. For now,
-                   this just converts uses of Fn::Join to Fn::Sub.
+    Usage: cfn-flip [OPTIONS] [INPUT] [OUTPUT]
+
+      AWS CloudFormation Template Flip is a tool that converts AWS
+      CloudFormation templates between JSON and YAML formats, making use of the
+      YAML format's short function syntax where possible."
+
+    Options:
+      -j, --json     Convert to JSON. Assume the input is YAML.
+      -y, --yaml     Convert to YAML. Assume the input is JSON.
+      -c, --clean    Performs some opinionated cleanup on your template.
+      -l, --long     Use long-form syntax for functions when converting to YAML.
+      -n, --no-flip  Don't convert. If you use -n in conjunction with -j or -y,
+                     the input format is assumed to be the same as the output
+                     format you specify.
+      --help         Show this message and exit.
+
 
 Cloudflip will detect the format of the input template and convert JSON to YAML and YAML to JSON, respectively.