fn framework -- add support for patch templates

kyaml/fn/framework/framework.go

@@ -256,6 +256,9 @@ type TemplateCommand struct {
 	// Templates is a list of templates to render.
 	Templates []*template.Template
 
+	// PatchTemplates is a list of templates to render into Patches and apply.
+	PatchTemplates []PatchTemplate
+
 	// TemplateFiles list of templates to read from disk which are appended
 	// to Templates.
 	TemplatesFiles []string
@@ -342,6 +345,12 @@ func (tc TemplateCommand) GetCommand() cobra.Command {
 			}
 		}
 
+		for i := range tc.PatchTemplates {
+			if err := tc.PatchTemplates[i].Apply(&rl); err != nil {
+				return err
+			}
+		}
+
 		var err error
 		if tc.MergeResources {
 			rl.Items, err = filters.MergeFilter{}.Filter(rl.Items)