Add upstream

wp-content/plugins/jetpack/extensions/blocks/markdown/markdown.php

@@ -0,0 +1,20 @@
+<?php
+/**
+ * Markdown Block.
+ *
+ * @since 6.8.0
+ *
+ * @package Jetpack
+ */
+
+/**
+ * The block depends on the Markdown module to be active for now.
+ * Related discussion: https://github.com/Automattic/jetpack/issues/10294
+ */
+if (
+	( defined( 'IS_WPCOM' ) && IS_WPCOM )
+	|| ( method_exists( 'Jetpack', 'is_module_active' ) && Jetpack::is_module_active( 'markdown' ) )
+) {
+	jetpack_register_block( 'jetpack/markdown' );
+}
+