Add 1209/BBD2, update URLs in 1209/BBD0, 1209/BBD1 - #1257

For chahor_rotary_keyboard, I think everything's fine. Open source hardware+software, includes PDF, etc.

For esp_hid_serial_bridge, there is no hardware embodiment which is generally requested for pidcode eligibility.

I would lean towards accepting this PR. But it will require additional review.

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esp_hid_serial_bridge is a firmware that will run on any esp32s3 device that has a USB port. This device, for example, is pretty minimalistic, but there are dozens of other options: https://lilygo.cc/products/t-dongle-s3

As for the new device (BBD2), the repository has the 3D model for the enclosure, and I'll add the schematics and assembly instructions soon.

BBD0 and BBD1 were prebviously approved, I just moved the repositories into a new organization, so that they are easier to find.