Add ElecFreaks new board

[Jaqster]

ElecFreaks is coming out with a new Arcade micro:bit shield. We've tested and approved already.

• [ ] Add new card to Download dialog

• [ ] Add new card to Homepage "Arcade Compatible Devices" row

• [ ] Add to Hardware page https://arcade.makecode.com/hardware

Here's the info - Name: micro:bit Arcade Pro Description: Use the micro:bit with Arcade Pro with a big screen, d-pad and Jacdac support. Link: https://shop.elecfreaks.com/products/elecfreaks-microsoft-makecode-micro-bit-arcade-pro Image:

[thomasjball]

added in https://github.com/microsoft/pxt-arcade/pull/7193

[thomasjball]

waiting for availability on their website.

    { 
        "name": "micro:bit Arcade Pro",
        "description": "Use the micro:bit with Arcade Pro with a big screen, d-pad and Jacdac support",
        "imageUrl": "/static/hardware/arcade-pro-ef.png",
        "url": "https://shop.elecfreaks.com/products/elecfreaks-microsoft-makecode-micro-bit-arcade-pro",
        "variant": "hw---n3"
    },