Theme Test Data site: Host or upload images to Github

[jp-imagines]

What

See WordPress/wordpress-playground#718 (comment) and WordPress/theme-test-data#82 (comment) for more details.

Media files on wpthemetestdata.wordpress.com are hosted on WordPress.com, i.e. wpthemetestdata.files.wordpress.com. CORS errors prevent these images from being imported into WordPress Playground sites.

It has been proposed that the media files be hosted on or uploaded to Github to bypass CORS errors.

Why

To allow this site's setup – including media files – to be used as a default option for testing themes in Playground.

How

Possible options:

1. Upload all images from wpthemetestdata.wordpress.com to Github and update the site to use these externally-hosted images and regenerate a new XML export file.
2. Provide a ZIP of all images on the site which can then be uploaded to Github by anyone. Media file references can then be updated in the existing XML file in the https://github.com/WordPress/theme-test-data/ repo.
3. Update references in the existing XML file to use i*.wp.com CDN URLs instead of *.files.wordpress.com URLs.

[flexseth]

@jp-imagines thanks for taking a look at this!

[jp-imagines]

@flexseth I spoke to a few colleagues about this, all of whom agreed with the recommendations from here: WordPress/theme-test-data#82 (comment)

Looks like a fix is already in the works in WordPress/theme-test-data#89 (using i*.wp.com CDN URLs), and the other solution would be to just download some or all of the media files from the test site and upload them to Github instead.

I'll close out this issue in light of that open PR and the discussions in the WP repos.