[Project] Support the use of small-caps

[sethwoodworth]

It's come up on twitter before, and this week in GITenberg/Lady-Susan_946/pull/1 that it would be great if we could support small-caps.

I can think of a few ways to go about it:

1. Use ᴛʜᴇ ᴜɴɪᴄᴏᴅᴇ ғᴏʀ sᴍᴀʟʟ ᴄᴀᴘɪᴛᴀʟ ʟᴇᴛᴛᴇʀs in the asciidoc source.
2. Add a custom style tag in our asciidoctor-htmlbook-template.
3. Extend asciidoc(tor) to support small-caps.

If we accept the argument that small-caps aren't semantic information, but formatting, then method 2 is probably the way we want to go.

[eshellman]

I agree that the second option is best