Docs: Style rules for glyphicons at narrow widths

[pedrottimark]

To implement the pictures in eslint/eslint#5774 (comment) when screen width is less than 768px:

• Display glyphicons inline instead of hiding them. That implies change to display incorrect thumbs-down and correct thumbs-up at left of example sentences instead of code wells; see Show if rule is enabled by eslint:recommended on rule page eslint#5774 (comment)
• Allow code elements to wrap, especially because some example sentences now have long options.

[pedrottimark]

1. Remove ad to avoid a regression!
2. Add icon class in replacement rules to dry out style selectors.
3. Add recommended and removed icons to lean toward Show if rule is enabled by eslint:recommended on rule page eslint#5774 (comment)

[nzakas]

Sorry, we lost track on this. Looks good!