* Clean up _flex.scss a little
This commit just cleans up the formating of _flex.scss by changing
it so that it uses a single `@include media-breakpoint-up` instead
of multiple. It also aligns all of the CSS properties so it looks
a bit nicer.
* Remove `-xs` from flex classes
* descriptions for getting started pages
* descriptions for layout
* add content page descriptions
* more descriptions, updates to some existing ones
* correct site url
* add social stuff to config for twitter cards
* add twitter meta tags; use large image for homepage and regular card for all others
* add the assets
* more site config
* more social shiz to partial, remove existing meta for the partial, remove page title from homepage for simpler if statements
I updated the doc with an example of a flex layout of 3 columns where the center column is specified as a `.col-xs-5` to show that other columns will resize no matter what the width of the center column.
Experienced bootstrap developers will expect to have to use an even number for the center column width when in reality any size will work.
I believe this is quite useful information and doesn't add too much to the docs.
Another option would be to make that initial example a `.col-xs-5` instead of a `.col-xs-6` to highlight this fact in the first place.
- Creates new flexbox grid Sass file in our docs assets
- Updates the Gruntfile to compile said new Sass file and minify the output
- Update notice on flexbox docs page for how it works
- Only enable compiled flexbox grid CSS in hosted docs site, not in dev (for easier and specific debugging of all flexbox features)
- Flexbox responsive behavior fixed with specific .col-{breakpoint} classes now added
- Dropped the make-col mixin in favor of a column-basics placeholder that we can extend across our grid infrastructure
- Updated docs to use required .col-xs-12 (as a safeguard for when folks enable flexbox mode--this isn't necessary in default grid mode)
- Update flexbox grid docs to include responsive docs, tweak some other bits too