update docs with a better explanation

README.md

@@ -1,3 +1,19 @@
 # spry
 
-Basic [Sprig](https://masterminds.github.io/sprig/) Template Rendering
+Basic [Sprig](https://masterminds.github.io/sprig/) Template Rendering.
+
+Functions similar to Helm Templating, but without the special K8s functions
+like `lookup`.
+
+## Usage Examples
+
+```bash
+$ ./spry
+Usage of ./spry:
+  -d string
+        Output delimiter between template files rendered (default "---")
+  -f value
+        Specify a values file (JSON or YAML)
+  -set value
+        Set a specific value (foo.bar=spam)
+```

main.go

@@ -80,8 +80,8 @@ var flags struct {
 }
 
 func init() {
-	flag.Var(&flags.values, "set", "")
-	flag.Var(&flags.valuesFiles, "f", "")
+	flag.Var(&flags.values, "set", "Set a specific value (foo.bar=spam)")
+	flag.Var(&flags.valuesFiles, "f", "Specify a values file (JSON or YAML)")
 	flag.StringVar(
 		&flags.outputDelimiter,
 		"d", "---",