✨ Add a PDF reader in docs

[AntoLC]

Feature Request

We can now integrate PDF on our docs, it could be nice to be able to see them directly from the editor.
An example is available here:
https://www.blocknotejs.org/examples/custom-schema/pdf-file-block

See:
https://github.com/TypeCellOS/BlockNote/tree/6aec6e2940d5732a5d6003f821faf218fdeed3eb/examples/06-custom-schema/04-pdf-file-block

[Kartik-Gangil]

Can I work on this issue? Please assign it to me.