Allow images in plugin and theme pages

[joostdevalk]

In the plugin and theme directory, embeds are allowed in the “readme”: authors can add videos to their pages, and often do. Weirdly, images are not allowed. Images are only allowed as “screenshots”, shown in a slider at the bottom of the page.

From a UX perspective, this makes no sense. If authors would be allowed to use inline images, they could make better pages, so I suggest allowing that.

I think we can make them work the same way screenshots now work; loading them from the assets folder. We could simply allow the standard image markdown, only allowing loading from /assets.

[Otto42]

Adding images adds a lot of extra download/bandwidth from our CDN. There would need to be some fairly heavy restrictions on what would be allowed.

[joostdevalk]

We could also allow remote embeds like we do for videos? I think loading them from WordPress.org owned assets would be my preference (we could limit to 1 or 2 MB or something?) but I’m open to anything.

[courane01]

This would also be helpful for https://meta.trac.wordpress.org/ticket/5926. Roughly the conversation left off in #meta Slack with pursuing the plugin owners uploading images to be the social share. Also related: https://meta.trac.wordpress.org/ticket/5826

cc: @webdevmattcrom @ndiego

[dd32]

I'm not a fan of the idea of supporting additional images. That's what the screenshots section is for.

I don't see "Videos are allowed" as a good reason to add images here. Videos IMHO should be part of the screenshots carousel, and not as inline embeds.