docs(parser): clarify project references

Closes #856

packages/parser/README.md

@@ -66,9 +66,11 @@ The following additional configuration options are available by specifying them
     ];
     ```
 
+  - Note that if you use project references, TypeScript will not automatically use project references to resolve files. This means that you will have to add each referenced tsconfig to the `project` field either separately, or via a glob.
+
   - Note that if this setting is specified and `createDefaultProgram` is not, you must only lint files that are included in the projects as defined by the provided `tsconfig.json` files. If your existing configuration does not include all of the files you would like to lint, you can create a separate `tsconfig.eslint.json` as follows:
 
-    ```js
+    ```jsonc
     {
       // extend your base config so you don't have to redefine your compilerOptions
       "extends": "./tsconfig.json",