Rename docs/LICENSE-DOCS to docs/LICENSE

It sounded weird.
refactoring: add & use .text-emphasis-variant() mixin
refactoring: add & use .bg-variant() mixin
add & use @modal-md Less var for uniformity
remove needless space character
Merge pull request #12271 from tlindig/modal_remove_needless_space

remove needless space character
Replace Normalize with Normalize.css
Merge pull request #12275 from ZDroid/ncss

Replace Normalize with Normalize.css
fix #12274
bump grunt-contrib-qunit to v0.4.0
Merge pull request #12276 from twbs/grunt-contrib-qunit

bump grunt-contrib-qunit to v0.4.0
add namespace `.bs` also to the event `dismiss.modal`
fix #12277

Thanks to @Quy for pointing these out.
present browser compatibility info in a table
copy
Move docs third-party libraries to a separate folder.
Fix typo in index.html
Make spelling of Less uniform throughout the docs
kill bottom margin on last docs section
Merge pull request #12281 from XhmikosR/vendor

Move docs third-party libraries to a separate folder.