[Select] Docs code highlighting overreached.

[lewiscowper]

• PR has tests / docs demo, and is linted. (n/a)
• Commit and PR titles begin with [ComponentName], and are in imperative form: "[Component] Fix leaky abstraction".
• Description explains the issue / use-case resolved, and auto-closes the related issue(s) (http://tr.im/vFqem).

Tiny swap for the floatingLabelText property, to the floatingLabelText, because "the" shouldn't be part of the inline code tag.

[mbrookes]

Thanks @lewiscowper