Move config file to right place in relation to node_modules

https://github.com/github/vscode-codeql/pull/2268#pullrequestreview-1371042057

Still need to consider how to ensure that the extension picks
up the right config.

extensions/ql-vscode/.markdownlint-cli2.cjs

@@ -8,4 +8,4 @@ module.exports = {
     outputFormatters: [
       [ "markdownlint-cli2-formatter-pretty", { "appendLink": true } ] // ensures the error message includes a link to the rule documentation
     ]
-}
+} 

extensions/ql-vscode/package.json

@@ -1422,7 +1422,7 @@
     "update-vscode": "node ./node_modules/vscode/bin/install",
     "format": "prettier --write **/*.{ts,tsx} && eslint . --ext .ts,.tsx --fix",
     "lint": "eslint . --ext .js,.ts,.tsx --max-warnings=0",
-    "lint:markdown": "markdownlint-cli2-config \"../../.markdownlint-cli2.cjs\" \"../../**/*.{md,mdx}\" \"!**/node_modules/**\"",
+    "lint:markdown": "markdownlint-cli2 \"../../**/*.{md,mdx}\" \"!**/node_modules/**\"",
     "format-staged": "lint-staged",
     "storybook": "start-storybook -p 6006",
     "build-storybook": "build-storybook",