function markdownSpace(code) {
  return (
    code === codes.horizontalTab ||
    code === codes.virtualSpace ||
    code === codes.space
  )
}
Check whether a character code is a markdown space.

A **markdown space** is the concrete character U+0020 SPACE (SP) and the
virtual characters M-0001 VIRTUAL SPACE (VS) and M-0002 HORIZONTAL TAB (HT).

In micromark, the actual character U+0009 CHARACTER TABULATION (HT) is
replaced by one M-0002 HORIZONTAL TAB (HT) and between 0 and 3 M-0001 VIRTUAL
SPACE (VS) characters, depending on the column at which the tab occurred.

@param {Code} code
  Code.
@returns {boolean}
  Whether it matches.