Add the release notes and assets v1.6 of the last BBC commit to this repo

[WernerBleisteiner]

The last BBC commit V1.6 from March 28 2025 has binary builds attached that work out of the box.
https://github.com/bbc/bmx/releases/tag/v1.6

As this repo mirrors mainly the archived original for now, and Until there will be a new version released here, having them integrated in this repo might lower the barrier and ease getting accustomed with bmx.
Thanks

[scenarnick]

Hi Werner, we will have to look into the feasibility of automating this without eating too much storage space.

[scenarnick]

Update - also see #19 we're working on a release to capture the current state and have an initial EBU-based release.