Add initial distributor CLI skeleton

internal/app/validate.go

@@ -0,0 +1,14 @@
+package app
+
+import (
+	"context"
+	"fmt"
+)
+
+type ValidateOptions struct {
+	Path string
+}
+
+func Validate(context.Context, ValidateOptions) error {
+	return fmt.Errorf("validate command: %w", ErrNotImplemented)
+}