David Elstob

### What happened? There appears to be a race condition bug with rendering custom embeds. I've created a custom embed as per the [example](https://tldraw.dev/examples/shapes/tools/custom-embed) - these embeds are simple web...

### What happened? The current `onDrop` handler for the TLDraw canvas immediately bails if the firing event doesn't have any files within the `dataTransfer`. ``` async function onDrop(e: React.DragEvent) {...