docs(website): help troubleshoot issues with multiple parsers (#5612)

* Help troubleshoot issues with multiple parsers

This might not be a perfect fit for the typescript-eslint docs, since this is specific to Vue.  However, I expect the issue effects other custom parsers as well. Including multiple parsers like this is counter intuitive because it seems like a mistake to include two "parser"s.  It would have been a huge help to me to have found this in the troubleshooting guide.  

more info:
https://eslint.vuejs.org/user-guide/#how-to-use-a-custom-parser

devs running into this issue:
vuejs/vue-eslint-parser#45 (comment)
https://stackoverflow.com/questions/66597732/eslint-vue-3-parsing-error-expected-eslint

* fix typos

* grouping vue related questions

* Apply suggestions from code review

* More syntax highlighting

Co-authored-by: Josh Goldberg <git@joshuakgoldberg.com>

docs/linting/TROUBLESHOOTING.md

@@ -86,6 +86,21 @@ module.exports = {
 };
 ```
 
+## I am running into errors when parsing TypeScript in my .vue files
+
+If you are running into issues parsing .vue files, it might be because parsers like [`vue-eslint-parser`](https://www.npmjs.com/package/vue-eslint-parser) are required to parse `.vue` files. In this case you can move `@typescript-eslint/parser` inside `parserOptions` and use `vue-eslint-parser` as the top level parser.
+
+```diff
+- "parser": "@typescript-eslint/parser",
++ "parser": "vue-eslint-parser",
+  "parserOptions": {
++     "parser": "@typescript-eslint/parser",
+      "sourceType": "module"
+  }
+```
+
+The `parserOptions.parser` option can also specify an object to specify multiple parsers. See the [`vue-eslint-parser` usage guide](https://eslint.vuejs.org/user-guide/#usage) for more details.
+
 ## One of my lint rules isn't working correctly on a pure JavaScript file
 
 This is to be expected - ESLint rules do not check file extensions on purpose, as it causes issues in environments that use non-standard extensions (for example, a `.vue` and a `.md` file can both contain TypeScript code to be linted).