Update usage to go up to 511 and update README with some info

README.md

@@ -1,5 +1,23 @@
 # httpwut
 
-CLI tool to look up HTTP status codes.
+CLI tool get HTTP status code information.
 
-_Probably not for other people to use._
+_This is a tool for me to learn Go, so you probably shouldn't use this._
+
+```
+λ httpwut -h        
+Get HTTP status code information
+usage: httpwut [100..511] [-v|--verbose] [-c|--cats] [-d|--dogs]
+
+λ httpwut 502       
+502 - Bad Gateway
+
+λ httpwut 502 --verbose
+502 - Bad Gateway
+The server, while acting as a gateway or proxy, received an invalid response from an inbound server it accessed while attempting to fulfill the request.
+https://www.rfc-editor.org/rfc/rfc9110.html#name-502-bad-gateway
+```
+
+Passing `--cats` and/or `--dogs` (you can do both at the time same) will open
+the status codes on https://http.cats and https://httpstatusdogs.com,
+respectively.

main.go

@@ -14,7 +14,7 @@ import (
 
 func usage() {
 	fmt.Println("Get HTTP status code information")
-	fmt.Printf("usage: %s [100..505] [-v|--verbose] [-c|--cats] [-d|--dogs]\n", os.Args[0])
+	fmt.Printf("usage: %s [100..511] [-v|--verbose] [-c|--cats] [-d|--dogs]\n", os.Args[0])
 }
 
 const helpUsage = "Print usage information"