feat: add layer definition api

internal/command/admin/definition/layer/root.go

@@ -0,0 +1,15 @@
+package layer
+
+import (
+	"github.com/urfave/cli/v2"
+)
+
+func Root() *cli.Command {
+	return &cli.Command{
+		Name:  "layer",
+		Usage: "Execute actions related to layer definitions",
+		Subcommands: []*cli.Command{
+			QueryCommand(),
+		},
+	}
+}