Update revision history

Author: pdimov

doc/array/changes.adoc

@@ -18,3 +18,4 @@ http://www.boost.org/LICENSE_1_0.txt
 * Removed obsolete compiler workarounds.
 * Changed `array<T, 0>::begin()`, `cbegin()`, `end()`, `cend()` to return `nullptr`, enabling `constexpr`.
   This matches the behavior of `std::array`.
+* Removed local `hash_value` overload; `boost::hash` supports array-like types natively.