Map tests for :first, :left, and :right pseudos to web-features

[foolip]

No description provided.

[foolip]

@mstensho these are the tests I could find by grepping which are clearly about the pseudos first and foremost. Lots of other tests use the pseudos though, are there any that I should include here? The scope of the feature per https://webstatus.dev/features/page-selectors is:

The :first, :left, and :right pseudo-classes select pages based on their position in sequence after pagination. They're often used with the page CSS property, to choose a print layout defined by the @page rule.

[mstensho]

:blank is missing from that list. Then again, there doesn't appear to be any tests for that. Blink doesn't support it, FWIW.

I did find a lot more more by grepping, but I guess I'm seeing the same results as you, and that you decided to omit them.

css/css-page/margin-boxes/content-009-print.html is fun though, and does require :left and :right to work, and checks that counters behave correctly on left and right pages.

[mstensho]

I already left a regular github comment.