switch browserName from "googlechrome" to "chrome" per @Jonahss in #12647
Merge pull request #12834 from twbs/sauce-chrome-name

switch browserName from "googlechrome" to "chrome"
fix #12836

Thanks @Quy.
move grid classes cascade explanation into main grid docs section
Merge pull request #12837 from twbs/grid-docs

move grid classes cascade explanation into main grid docs section
grunt dist
update GitHub issue link in comment