readme updated

Author: typomedia

README.md

@@ -4,6 +4,16 @@ A cli utility to check the syntax of XML files.
 
 It is written in Rust, and uses the [xml-rs](https://crates.io/crates/xml-rs) library.
 
+## USAGE
+    xmllint <file>
+
+## ARGS
+    <file>    XML file to parse
+
+## OPTIONS
+    -h, --help       Print help information
+    -V, --version    Print version information
+
 ## Building 
 
     make build