feat: switch from deprecated eslint-plugin-markdown to @eslint/markdown (#2297)

## PR Checklist

- [x] Addresses an existing open issue: fixes #2273
- [x] That issue was marked as [`status: accepting
prs`](https://github.com/JoshuaKGoldberg/create-typescript-app/issues?q=is%3Aopen+is%3Aissue+label%3A%22status%3A+accepting+prs%22)
- [x] Steps in
[CONTRIBUTING.md](https://github.com/JoshuaKGoldberg/create-typescript-app/blob/main/.github/CONTRIBUTING.md)
were taken

## Overview

Swaps in-place from the old plugin to the new.

This isn't _quite_ what the issue suggested, but I plan on sending a
fast follow for the more full #1926 to migrate off of Markdownlint. I
think it'll be nice to have a reference version of CTA that uses
`@eslint/markdown` instead of `eslint-plugin-markdown` _before_ the
removal of Markdownlint. Just in case it's useful.

🎁

Author: JoshuaKGoldberg

docs/FAQs.md

@@ -108,8 +108,6 @@ Then:
 1. In `tsdown.config.ts`, change the [tsdown `format` option](https://tsdown.dev/options/output-format) from `["esm"]` to `["cjs", "esm"]`
 2. Add a [`package.json` `"exports"` entry](https://nodejs.org/api/packages.html#subpath-exports) like:
 
-   <!-- eslint-disable jsonc/sort-keys -->
-
    ```json package.json
    {
    	"exports": {
@@ -125,8 +123,6 @@ Then:
    }
    ```
 
-   <!-- eslint-enable jsonc/sort-keys -->
-
 That should be it!
 
 To be safe, consider checking with [arethetypeswrong](https://arethetypeswrong.github.io):

eslint.config.js

@@ -10,10 +10,10 @@ If you're interested in learning more, see the 'getting started' docs on:
 
 import comments from "@eslint-community/eslint-plugin-eslint-comments/configs";
 import eslint from "@eslint/js";
+import markdown from "@eslint/markdown";
 import vitest from "@vitest/eslint-plugin";
 import jsdoc from "eslint-plugin-jsdoc";
 import jsonc from "eslint-plugin-jsonc";
-import markdown from "eslint-plugin-markdown";
 import n from "eslint-plugin-n";
 import packageJson from "eslint-plugin-package-json";
 import perfectionist from "eslint-plugin-perfectionist";
@@ -82,7 +82,14 @@ export default defineConfig(
 		extends: [jsonc.configs["flat/recommended-with-json"]],
 		files: ["**/*.json"],
 	},
-	{ extends: [markdown.configs.recommended], files: ["**/*.md"] },
+	{
+		extends: [markdown.configs.recommended],
+		files: ["**/*.md"],
+		rules: {
+			// https://github.com/eslint/markdown/issues/294
+			"markdown/no-missing-label-refs": "off",
+		},
+	},
 	{
 		extends: [tseslint.configs.disableTypeChecked],
 		files: ["**/*.md/*.ts"],

package.json

@@ -71,9 +71,9 @@
 	"devDependencies": {
 		"@eslint-community/eslint-plugin-eslint-comments": "4.5.0",
 		"@eslint/js": "9.39.1",
+		"@eslint/markdown": "7.5.1",
 		"@prettier/sync": "0.6.1",
 		"@release-it/conventional-changelog": "10.0.2",
-		"@types/eslint-plugin-markdown": "2.0.2",
 		"@types/html-to-text": "9.0.4",
 		"@types/js-yaml": "4.0.9",
 		"@types/lodash": "4.17.21",
@@ -91,7 +91,6 @@
 		"eslint": "9.39.1",
 		"eslint-plugin-jsdoc": "61.4.1",
 		"eslint-plugin-jsonc": "2.21.0",
-		"eslint-plugin-markdown": "5.1.0",
 		"eslint-plugin-n": "17.23.1",
 		"eslint-plugin-package-json": "0.85.0",
 		"eslint-plugin-perfectionist": "4.15.1",