* Prevent focus into closed offcanvas

- Fixes typo with "with at" in "horizontal with at the small breakpoint"

* Move helpful code comments

* Add .carousel-fade option to Sass

* Document example of the fade carousel

* more logical warning of the .active class on carousel items

* Add .dropdown-item-text class

* Add example of plain text within a .dropdown-menu, too

* reorganize, simple/clearer headings

Currently bootstrap only provides 4 variations of `width` and `height` css utilities, which are:

1. 25%
2. 50%
3. 75%
4. 100%.

Here, I'm adding `auto` to the list. This is useful when we need to reset the width/height value
back to the browser default value at some point.

Opera 19 was released in January 2014 and auto-updates so I suggest no need to mention about browser support for this old version.

Removed '**Animated progress bars don't work in Opera 12**—as they don't support CSS3 animations.' note.

Bootstrap 4 doesn't (and doesn't need to) support the ancient Opera 12 released in 2012 with a 0.04% marketshare so no need to mention.

Convert them to 8-bit and compress them with optipng and zopflipng.

Before: 902 KB (923,969 bytes)
After:  431 KB (441,372 bytes)

* Prevent print utils from overriding all other display utils

Fixes #25221.

I agree with the referenced issue—this is unexpected and also causes a serious bug when mixed with other utility classes. This wasn't an issue in v3 given we had different utilities for hiding that weren't focused on display property.

* Add printing changes to migration docs

* unrelated heading sentence case change

* List out all .d-print- classes

* Add order-*-last grid class

* copy updates

Closes #25231

* Update copyright range to include 2018

* Extend copyright date range on new files from 2017 to include 2018

* Make dropright snippet the same as demo

* Add missing .dropdown-toggle-split class

* Make clear the split button label the same as demo

* heading for better linking

* tell folks where to start

* more headings

* required keys section added, closes #25293

* fix cover nav

* Improve signin visuals and alignment with that flexbox love

* rewrite cover example in flexbox

* lighten signin bg

* first pass at pricing example

* redo examples index with data file

* tighten up spacing a bit

* update navbar descriptions

* link pricing

* move that back

* property order

* Fix test errors.

* Compress pricing.png.

* add form validation example

* remove that

* rename that

* restyle and space out

* fix errors

* change order

* cleanup album css and styles

* tweak examples index

* make it a badge

* options

* improve sticky footer alignment

* redesign example index

* brand new blog layout

* start new screenshots

* new product example page a la apple

* add email field

* fix linter, remove unused blog css

* hook up feather icons to start

* redo dashboard

* fix linting

* add floating labels example

* formatting

* formatting

* lint

* fix values o...

fixes #25288

Also, refactor ESLint and stylelint config files; now everything will work from our root dir.

* Deprecate hover media query shim and mixins

Fixes #25195.

This never was completed or fully implemented, and the docs are inaccurate as to what browsers are currently affected by this stickied hover problem. This PR aims to update the docs and deprecate the shim from our mixins and only return the pseudo-classes. To reflect the order of these states used elsewhere (e.g., our button styles), I've also updated the order of each within the mixin.

* Mention in docs and variables that it's deprecated

Due to a severe performance bug in Chrome (see https://bugs.chromium.org/p/chromium/issues/detail?id=800522) and due to the fact that (with the exception of IE/Edge on Windows desktop with touchscreen) all modern browsers now optimize the click delay away anyway, this optimization is not needed.

Closes https://github.com/twbs/bootstrap/issues/24670