message: Improve the split split's description
diff: @@ -588,9 +588,9 @@ provides, and a blurb about how each is intended to be used.
  <DT>\link ranges::view::sliding_fn `view::sliding`\endlink</DT>
  <DD>Given a range and a count `n`, place a window over the first `n` elements of the underlying range. Return the contents of that window as the first element of the adapted range, then slide the window forward one element at a time until hitting the end of the underlying range.</DD>
  <DT>\link ranges::view::split_fn `view::split`\endlink</DT>
  - <DD>Given a source range and a delimiter specifier, split the source range into a range of ranges using the delimiter specifier to find the boundaries. The delimiter specifier can be a value or a subrange. The delimiter character(s) are excluded from the resulting range of ranges.</DD>
  + <DD>Given a source range and a delimiter specifier, split the source range into a range of ranges using the delimiter specifier to find the boundaries. The delimiter specifier can be an element or a range of elements. The elements matching the delimiter are excluded from the resulting range of ranges.</DD>
  <DT>\link ranges::view::split_when_fn `view::split_when`\endlink</DT>
  - <DD>Given a source range and a delimiter specifier, split the source range into a range of ranges using the delimiter specifier to find the boundaries. The delimiter specifier can be a predicate or a function. The predicate should take a single argument of the range's reference type and return true if and only if the element is part of a delimiter. The function should accept current/end iterators into the source range and return `make_pair(true, iterator_past_the_delimiter)` if the current position is a boundary; otherwise, `make_pair(false, cur)`. The delimiter character(s) are excluded from the resulting range of ranges.</DD>
  + <DD>Given a source range and a delimiter specifier, split the source range into a range of ranges using the delimiter specifier to find the boundaries. The delimiter specifier can be a predicate or a function. The predicate should take a single argument of the range's reference type and return `true` if and only if the element is part of a delimiter. The function should accept an iterator and sentinel indicating the current position and end of the source range and return `std::make_pair(true, iterator_past_the_delimiter)` if the current position is a boundary; otherwise `std::make_pair(false, ignored_iterator_value)`. The elements matching the delimiter are excluded from the resulting range of ranges.</DD>
  <DT>\link ranges::view::stride_fn `view::stride`\endlink</DT>
  <DD>Given a source range and an integral stride value, return a range consisting of every *N*<SUP>th</SUP> element, starting with the first.</DD>
  <DT>\link ranges::view::tail_fn `view::tail`\endlink</DT>
  