Setup emailing

[shenanigansd]

Closes #3

Tested with

@app.post("/test-email/{email_address}", status_code=HTTP_202_ACCEPTED, response_class=Response)
async def test_email(
    email_address: str,
    graph_client: Annotated[GraphServiceClient, Depends(build_graph_client)],   
) -> None:
    await send_mail(
        graph_client=graph_client,
        to_addresses=[email_address],
        bcc_addresses=[],
        subject="Test",
        content="Test",
    )