Localization-friendly by default

[maureenlholland]

general issue best described here: mozilla/bedrock#12344 (comment)

Things we might want to consider:

• smaller content containers with larger fonts gets hyphens: auto styling
• updating docs to suggest leaving more room to layouts meant to accommodate localized content
• adding truncate utility with guidelines for use

update: l10n guidelines https://mozilla-l10n.github.io/documentation/localization/dev_best_practices.html#create-localizable-ui

[maureenlholland]

extensive RTL style guide here: https://rtlstyling.com/posts/rtl-styling

[craigcook]

We're pretty l10n-friendly already though could make a few improvements. A lot comes down to writing good localizable content, which isn't really a Protocol thing (at least until we incorporate a styleguide for copy).