Merge pull request #54 from arschles/fix-readme

fixing the readme to indicate err return

README.md

@@ -56,11 +56,11 @@ To ignore files, pass in regexes using -ignore, for example:
 To access asset data, we use the `Asset(string) []byte` function which
 is included in the generated output.
 
-	data := Asset("pub/style/foo.css")
-	if len(data) == 0 {
+	data, err := Asset("pub/style/foo.css")
+	if err != nil {
 		// Asset was not found.
 	}
-	
+
 	// use asset data