[[ Player ]] Add release note for Windows MediaFoundation player control

This patch adds a release note for the change of implementation in the
Windows player control from DirectShow to MediaFoundation.

docs/notes/feature-windows_mediafoundation_player.md

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+# Windows MediaFoundation Player Control
+
+Due to the recent decision by Apple to end support for QuickTime on
+Windows, the player implementation on that platform has been replaced
+with one based on DirectShow.  This is a multimedia API that is
+available by default on all versions of Windows supported by LiveCode.
+
+The new implementation should function as a drop-in replacement for
+the old one, though some properties are not yet implemented.
+
+### Property Changes
+On Windows, the behaviour of some properties of the player control have changed.
+
+- The **tracks**, **trackCount**, and **enabledTracks** previousy did not work
+  on Windows but now do.
+- The **loadedTime** property no longer works on Windows, but will be re-enabled
+  if possible in a subsequent release.
+
+### Supported File Formats
+
+Media format support in the new Windows player control depends on
+which codecs are installed.
+
+A list of the
+[file formats and compression types available as standard](https://docs.microsoft.com/en-us/windows/win32/medfound/supported-media-formats-in-media-foundation)
+on Windows is available in the Windows Dev Center documentation