fix lint

Author: Murderlon

blog/2024-07-3-uppy-4.0.md

@@ -34,6 +34,8 @@ uppy.on('file-added', (file) => {
 
 One important thing to note are the new generics on `@uppy/core`.
 
+<!-- eslint-disable @typescript-eslint/no-non-null-assertion -->
+
 ```ts
 import Uppy from '@uppy/core';
 // xhr-upload is for uploading to your own backend.