Add a styling for :guilabel: inline markup.

[jonathanj]

Fixes #262.

:guilabel: is a convenient way to hint that a particular action in a user interface is available, unfortunately in the RTD theme there is no styling for it, so the markup appears as plain text.

[agjohnson]

Thanks for the addition! In terms of styling, here's a few things:

• The border box looks like it extends past the line-height, this will cause paragraph lines to overlap or look ragged.
• There should be a bit more margin on sides of the highlight
• I'm hesitant to force all caps, though if it's a pattern we're using on elements in the same way, I think it makes sense. We force caps on nav elements, I don't recall immediately where else we might
• Also, the styling above implies a button element, whereas the :guilabel: could be describing any element

[jonathanj]

Thanks for the feedback @agjohnson!

• The border box was basically on the edge of line-height, I've shrunk it down so that it fits more comfortably.
• I added a small horizontal margin. I'm not sure what variable / ratio to base this off, I used base-line-height but it seems like a letter spacing variable would be better. Is there one?
• I don't have a strong opinion on the capitals, it was mostly a personal style preference but I think they're a little clearer (there's no letter ambiguity like there can be in lowercase) and stand out more. I don't see a pattern in the use of all caps throughout the theme, why are the section captions in the sidebar capitals, for example?

Some screenshots again, on my particular resolution these two words appear right underneath one another, so it's a good illustration for the border box size.

[Makc37]

Reviewed 1 of 5 files at r1, 4 of 4 files at r2.
Review status: all files reviewed at latest revision, all discussions resolved, some commit checks failed.

---

Comments from Reviewable

[jonathanj]

@Makc37 I've resolved the conflicts with master.

[ericholscher]

Seems like this can be merged with a rebase. @agjohnson any objection?

[agjohnson]

Updates look good, I just a noted on the color variable used.

[agjohnson]

This shouldn't piggy back off of class-color and should set it's own color, or use something more appropriate than class-color.

[ericholscher]

Fixed this in a new branch and merged.