Closes #11410

Closes #11370

This will allow easy deployment into a public directory with [component-installer](https://github.com/RobLoach/component-installer) or other various methods.

Correct Sass/Less capitalization

**See:**
* http://sass-lang.com
* http://lesscss.org

Add filter "email" to "at"

Fix typo

Sets the same filters to all envelope icons and adds a `message`
filter.

Close: #10788

Duplicate keywords

FA5 Pre-order links

Fix cheatsheet print layout

This change makes the W3C Validator happier.

Ref: https://validator.w3.org/docs/errors.html#ve-394

This PR changes the print layout, showing three icons per row instead of
one. In this way we can solve an issue with the Bootstrap grid, which
for some reason limits the output to three pages when printing the
cheatsheet.

Fix: #10395

Updating Docs Site Post-Font Awesome 5 Kickstarter

Add time left on Kickstarter to banner

Remove duplicate v4.6.3 line in Changelog

Fix script injection by using _.template escaping

README.md in the root folder is generated by the build process.
This commit prevents badge from being lost

Ref: #10179

Add Changelog episode badge to README

Links to: https://changelog.com/podcast/226

corrected aria-hidde_ to aria-hidden

I notice the aria-hidden value was incomplete.  

cheers