(whitespace): Set :version tag to 23.1.

(whitespace): Set :version tag to 23.1.
(whitespace-turn-off, whitespace-toggle-options): Fix typos.
(whitespace-style, whitespace-chars, whitespace-space, whitespace-hspace,
whitespace-tab, whitespace-newline, whitespace-trailing, whitespace-line,
whitespace-space-before-tab, whitespace-indentation, whitespace-empty,
whitespace-space-after-tab, whitespace-hspace-regexp, whitespace-space-regexp,
whitespace-tab-regexp, whitespace-trailing-regexp,
whitespace-space-before-tab-regexp, whitespace-indentation-regexp,
whitespace-empty-at-bob-regexp, whitespace-empty-at-eob-regexp,
whitespace-space-after-tab-regexp, whitespace-line-column,
whitespace-display-mappings, global-whitespace-toggle-options,
whitespace-cleanup, whitespace-cleanup-region, whitespace-interactive-char):
Doc fixes.