B2B-88: add starter kit structure and elements

packages/cms/keystatic/src/custom-components.tsx

@@ -0,0 +1,36 @@
+import type { ComponentType } from 'react';
+
+import type { Schema } from '@markdoc/markdoc';
+
+type Component = ComponentType<unknown>;
+
+/**
+ * @name CustomMarkdocComponents
+ * @description Custom components for Markdoc. Please define your custom components here.
+ * @example
+ *
+ * ```ts
+ * function Youtube(props: { src: string }) { ... }
+ *
+ * export const CustomMarkdocComponents: Record<string, React.ComponentType<never>> = {
+ *   Youtube,
+ * };
+ */
+export const CustomMarkdocComponents: Record<string, Component> = {
+  // define your custom components here
+};
+
+/**
+ * @name CustomMarkdocTags
+ * @description Custom tags for Markdoc. Please define your custom tags here.
+ * @example
+ * export const CustomMarkdocTags = {
+ *  youtube: {
+ *     render: "Youtube",
+ *     selfClosing: true,
+ *  }
+ * }
+ */
+export const CustomMarkdocTags: Record<string, Schema> = {
+  // define your custom tags here
+};