Machine-readable configuration list in JSON for web firmware tools

[nekomona]

An idea from the web firmware tool group about automating flasher page for variants on different branches.

There could be a manually-maintained JSON file listing all the possible configurations for define.h, debug.h and so on. So that for experimental implementations, the contributors could just update their changes into the JSON file, and the web firmware tool could parse that JSON, show the configuration options, and works for the new branch automatically.

At an early stage, the format and content of the JSON are up to discussion. A brief idea is that this would simplify the process of testing new firmware branches, where new branches could be rapidly tested by the people don't having firmware dev environment, without manual modifications & checking on the web firmware tools.