`[role]`s are retained for now as they are harmless although
redundant when added to HTML5 elements.
`role="contentinfo"` on `footer` is a special case to address
a known VoiceOver bug.
Bug: T66477
Change-Id: I540d9a41fc7fd580c5d61b90480e8745ae145850
Keys prefixed with msg- should relate to i18n keys. Fix the existing
template variables where that's not the case.
Change-Id: I33587a09a9803a3667eaeea95ce3e1753439f413
Using 'skin' as entrance point files, similar to already existing
convention in MediaWiki land with 'skin.json' or 'SkinVector.php' as
example in Vector skin. Replacing Apache inspired 'index' convention.
Also renaming legacy to 'skin-legacy' to be clear on file base that it's
a modification of 'skin'.
Bug: T249073
Change-Id: Ief1c469724d4ffe238d307407c3ddb46f2e1abfa