Boot.bin not being created in releases

[davidpcls]

For releases after 3.0 there appears to be no boot.bin file. Also there additional expected files missing:

• boot.bin
• devicetree.dtb
• uEnv.txt

These are all necessary according to the documentation on how to create a bootable SD card.

[tomtrafford]

For releases after 3.0, those files are created by the PandABlocks-FPGA repository. The files have been combined into one boot*.zip file in the releases published here: https://github.com/PandABlocks/PandABlocks.github.io/releases