Add support for Lua input (#1810)

pkg/yqlib/decoder.go

@@ -18,6 +18,7 @@ const (
 	TSVObjectInputFormat
 	TomlInputFormat
 	UriInputFormat
+	LuaInputFormat
 )
 
 type Decoder interface {
@@ -41,6 +42,8 @@ func InputFormatFromString(format string) (InputFormat, error) {
 		return TSVObjectInputFormat, nil
 	case "toml":
 		return TomlInputFormat, nil
+	case "lua", "l":
+		return LuaInputFormat, nil
 	default:
 		return 0, fmt.Errorf("unknown format '%v' please use [yaml|json|props|csv|tsv|xml|toml]", format)
 	}