Twenty Fifteen: remove fonts as a style dependency.

Props obenland, SergeyBiryukov. Fixes #30678.
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git-svn-id: http://core.svn.wordpress.org/trunk@30822 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Fifteen: update readme.txt file, props iamtakashi. See #30675.
Built from https://develop.svn.wordpress.org/trunk@30833


git-svn-id: http://core.svn.wordpress.org/trunk@30823 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Fifteen: update archive pagination links to use `aria-hidden` for better accessibility.

Props SergeyBiryukov, fixes #30152.
Built from https://develop.svn.wordpress.org/trunk@30834


git-svn-id: http://core.svn.wordpress.org/trunk@30824 1a063a9b-81f0-0310-95a4-ce76da25c4cd