Feature: Add support for -webkit-hyphens & -ms-hyphens

[SteelWagstaff]

Description

Reported by Thomas Dumm:

I looked at a book (using the Malala theme) on my iphone with iOS13. I noticed that the justified text had many large “holes” and that no hyphenation was happening on the iphone despite the hyphens: auto CSS rule. I then added -webkit-hyphens: auto to the custom css and the justified text looked nice on the iphone too. Apparently iOS (also the latest version 13) only knows -webkit-hyphens. So maybe it makes sense to add -webkit-hyphens auto to the right place in the theme css (or in buckram?). Maybe include the -ms prefixes too?

https://caniuse.com/#feat=css-hyphens

Hyphens are set in McLuhan in a few places (

pressbooks-book/packages/buckram/assets/styles/components/elements/_paragraphs.scss

Lines 31 to 40 in 46e41fb

	// Hyphenation
	body,
	p {
	hyphens: $para-hyphens;
	hyphenate-before: $para-hyphenate-before;
	hyphenate-after: $para-hyphenate-after;
	hyphenate-lines: $para-hyphenate-lines;
	}

pressbooks-book/assets/styles/components/_elements.scss

Line 114 in d583abd

$para-hyphens: auto !default;

pressbooks-book/packages/buckram/assets/styles/variables/_elements.scss

Line 635 in c7f4949

$para-hyphens: auto !default;

It also looks like several themes use -webkit-hyphens. See https://github.com/search?q=org%3Apressbooks+%22-webkit-hyphens%22&type=Code

[SteelWagstaff]

We removed justification from the Malala theme. Need to see if the hyphen issue still persists.