Add winstd::mutex

Signed-off-by: Simon Rozman <simon@rozman.si>

include/WinStd/Win.h

@@ -1,4 +1,4 @@
-/*
+/*
     SPDX-License-Identifier: MIT
     Copyright © 1991-2023 Amebis
     Copyright © 2016 GÉANT
@@ -1441,6 +1441,13 @@ namespace winstd
     ///
     typedef win_handle<INVALID_HANDLE_VALUE> process_snapshot;
 
+    ///
+    /// Mutex handle wrapper
+    ///
+    /// \sa [CreateMutexW function](https://learn.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-createmutexw)
+    ///
+    typedef win_handle<NULL> mutex;
+
     ///
     /// File handle wrapper
     ///