[css-transitions] Fix backwards shadow-list interp.

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extra : rebase_source : 0cf1e0686fa33a18b9fe33bfddddfcd625396e0c
[css-flexbox] Update DoC

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extra : rebase_source : 20ad564901a6e13329096727b9903587f9f0b6b4
[css-grid] typo

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extra : rebase_source : 9c328152481325f9ccae6c4511ebfc4456a0956d
[css-grid] Switch to a dl