manifest: add 'add' subcommand

internal/commands/manifest_add.go

@@ -30,9 +30,16 @@ func ManifestAdd(logger logging.Logger, pack PackClient) *cobra.Command {
 
 			indexName := args[0]
 			manifest := args[1]
+			all := false
+
+			if flags.All {
+				all = flags.All
+			}
+
 			if err := pack.AddManifest(cmd.Context(), client.AddManifestOptions{
 				Index:    indexName,
 				Manifest: manifest,
+				All:      all,
 			}); err != nil {
 				return err
 			}

pkg/client/add_manifest.go

@@ -1,16 +1,23 @@
 package client
 
-import "context"
+import (
+	"context"
+
+	"github.com/buildpacks/imgutil/local"
+)
 
 type AddManifestOptions struct {
-	Index        string
-	Manifest     string
-	Architecture string
-	OS           string
-	Variant      string
-	All          bool
+	Index    string
+	Manifest string
+	All      bool
 }
 
 func (c *Client) AddManifest(ctx context.Context, opts AddManifestOptions) error {
+
+	err := local.AppendManifest(opts.Index, opts.Manifest)
+	if err != nil {
+		return err
+	}
+
 	return nil
 }