CircleCI: Build full-site-editing

[Copons]

Changes proposed in this Pull Request

• Add a CircleCI job that creates artifacts from the dist folder containing plugin and theme.
• Update the whole build system of the app (check the updated readme).

Testing instructions

• On CircleCI, check the artifacts contained in the build-full-site-editing job.
• Make sure they contain all the built files and the source and PHP files as well.
• Locally, run the following scripts, and make sure they work as expected.
  • npx lerna run dev --scope='@automattic/full-site-editing'
  • npx lerna run build --scope='@automattic/full-site-editing'
• Don't forget to update the symlinks to the dist (check the updated readme) if needed!

Fix #32488 (see also D27231-code)

[matticbot]

Test live: https://calypso.live/?branch=update/32419-full-site-editing-circle-ci-workflow

[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

Generated by performance advisor bot at iscalypsofastyet.com.

[vindl]

Tests well for me! I left some optional notes.

[vindl]

Any reason for naming this script php instead of something more related to copying?

[Copons]

No reasons, I ran out of good names, and that has been called php for a long time because of its original intent of only copying php files.
I'll update it into copy-to-dist and call it a day.

[vindl]

In addition to this one, it seems to be also creating another dist subfolder in full-site-editing-plugin. Is that intended? (asking because it was confusing for me at first)

[Copons]

I believe that might be the dist folder created by the previous build system, which gets copied into the new dist.
Try deleting all three dist folders and rebuild: that shouldn't be there anymore. 🙂

[vindl]

Yeah, I was suspecting I was doing something wrong and tried deleting them and rebuilding (seemed to be coming back). Anyway, probably an error on my end so feel free to proceed. :)