add initial marp implementation with sample content and build configuration

node_modules/@marp-team/marpit/lib/markdown/background_image.js

@@ -0,0 +1,36 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = exports.backgroundImage = void 0;
+var _plugin = _interopRequireDefault(require("../plugin"));
+var _advanced = _interopRequireDefault(require("./background_image/advanced"));
+var _apply = _interopRequireDefault(require("./background_image/apply"));
+var _parse = _interopRequireDefault(require("./background_image/parse"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit background image plugin.
+ *
+ * Convert image token to backgrounds when the alternate text includes `bg`.
+ *
+ * When Marpit inline SVG mode is disabled, the image will convert to
+ * `backgroundImage` and `backgroundSize` spot directive. It supports only
+ * single background and resizing by using CSS.
+ *
+ * When inline SVG mode is enabled, the plugin enables advanced background mode.
+ * In addition to the basic background implementation, it supports multiple
+ * background images, filters, and split background.
+ *
+ * @function backgroundImage
+ * @param {MarkdownIt} md markdown-it instance.
+ */
+function _backgroundImage(md) {
+  (0, _parse.default)(md);
+  (0, _apply.default)(md);
+  (0, _advanced.default)(md);
+}
+const backgroundImage = exports.backgroundImage = (0, _plugin.default)(_backgroundImage);
+var _default = exports.default = backgroundImage;