[linter] Review linter setup (#3783)

- [2b395b9f] Fix command to lint markdown in `CONTRIBUTING.md`
- [fed4c86c] Re-activate JSDoc ESLint plugin and fix linting issues (As
far as I remember, we deactivated it when we upgraded to ESLint 9
because it was not compatible with it. But its now.)
- [a3d2064b] Refactor ESLint config to use `defineConfig` and
`globalIgnores` ([these are like new
defaults](https://eslint.org/blog/2025/03/flat-config-extends-define-config-global-ignores/))
- [a3d2064b] Replace `eslint-plugin-import` with
`eslint-plugin-import-x`
(https://github.com/es-tooling/module-replacements/blob/main/docs/modules/eslint-plugin-import.md)
- [86a185b6] Switch Stylelint config to flat format and simplify
Stylelint scripts (like we already did for ESLint and prettier)
  - [f5a2c541] Fix some typos

modules/default/utils.js

@@ -5,7 +5,7 @@
  * @param {boolean} useCorsProxy A flag to indicate
  * @param {Array.<{name: string, value:string}>} requestHeaders the HTTP headers to send
  * @param {Array.<string>} expectedResponseHeaders the expected HTTP headers to receive
- * @param {string} basePath, default /
+ * @param {string} basePath The base path, default is "/"
  * @returns {Promise} resolved when the fetch is done. The response headers is placed in a headers-property (provided the response does not already contain a headers-property).
  */
 async function performWebRequest (url, type = "json", useCorsProxy = false, requestHeaders = undefined, expectedResponseHeaders = undefined, basePath = "/") {
@@ -38,7 +38,7 @@ async function performWebRequest (url, type = "json", useCorsProxy = false, requ
  * @param {string} url the url to fetch from
  * @param {Array.<{name: string, value:string}>} requestHeaders the HTTP headers to send
  * @param {Array.<string>} expectedResponseHeaders the expected HTTP headers to receive
- * @param {string} basePath, default /
+ * @param {string} basePath The base path, default is "/"
  * @returns {string} to be used as URL when calling CORS-method on server.
  */
 const getCorsUrl = function (url, requestHeaders, expectedResponseHeaders, basePath = "/") {