Introduce options.markdownItFactory (and remove options.markdownItPlugins) so the markdown-it parser can be removed as a direct dependency because it is no longer used by default.

lib/markdownlint.d.mts

@@ -357,6 +357,23 @@ export type Rule = {
      */
     function: RuleFunction;
 };
+/**
+ * Method used by the markdown-it parser to parse input.
+ */
+export type MarkdownItParse = (src: string, env: any) => any[];
+/**
+ * Instance of the markdown-it parser.
+ */
+export type MarkdownIt = {
+    /**
+     * Method to parse input.
+     */
+    parse: MarkdownItParse;
+};
+/**
+ * Gets an instance of the markdown-it parser. Any plugins should already have been loaded.
+ */
+export type MarkdownItFactory = () => MarkdownIt;
 /**
  * Configuration options.
  */
@@ -390,9 +407,9 @@ export type Options = {
      */
     handleRuleFailures?: boolean;
     /**
-     * Additional plugins.
+     * Function to create a markdown-it parser.
      */
-    markdownItPlugins?: Plugin[];
+    markdownItFactory?: MarkdownItFactory;
     /**
      * True to ignore HTML directives.
      */