Create build repo or branch from each commit to trunk to aid git bisects.

[peterwilsoncc]

As the Gutenberg repo makes heavy use of NPM dependencies, it makes a git bisect difficult as one needs to run npm i; npm run build during each step. For short time frames running the watch command may work but for the initial commit to WordPress-Develop during the release cycle, it usually is not.

When running a git bisect on WordPress-Develop, it's possible to use https://github.com/wordPress/wordpress to find the reference without the need to run a build on each step.

For debugging purposes, I think maintaining a build repo or branch of Gutenberg would be helpful. Each commit to trunk (and possibly wp/* branches) would improve the bisect workflow and improve the accuracy.

The commit message format for the build repo would be similar to WordPress/WordPress commit logs:

[Gutenberg commit message]
Built from https://github.com/WordPress/gutenberg/commit/hash

cc @gziolo @adamziel