Merge pull request #12287 from Quy/master

Add table's .info variant to migration guide
Added WAI-ARIA roles to examples/theme/index.html (document, main)

https://en.wikipedia.org/wiki/WAI-ARIA

http://www.w3.org/TR/wai-aria/roles
Dustin' the docs: Typos, Grammar, etc. in css.html
fix anomalous indentation
grammar: fix plural possessive
make WP8 device-width hack code fully consistent between docs HTML & docs JS
add X-UA-Compatible <meta> to basic template
Merge pull request #12288 from twbs/x-ua-compat

add X-UA-Compatible <meta> to basic template
Improve <meta> tags
Merge pull request #12292 from ZDroid/meta

Improve <meta> tags
Make head elements order uniform across templates and examples
Additional changes to #12275 and #12292