SDL: doxygen: manually move SDL_CloseAudioDevice docs from wiki.

From 8104c9e3ebf3a5e3ef3fe322ff4caee011a751cc Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Wed, 4 Aug 2021 00:02:39 -0400
Subject: [PATCH] doxygen: manually move SDL_CloseAudioDevice docs from wiki.

Apparently we don't fill these in from the wiki if the function doesn't
have _any_ documentation already. That's a bug, I think.
---
 include/SDL_audio.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/include/SDL_audio.h b/include/SDL_audio.h
index 39ebe0e18..0aa001764 100644
--- a/include/SDL_audio.h
+++ b/include/SDL_audio.h
@@ -1151,6 +1151,27 @@ extern DECLSPEC void SDLCALL SDL_UnlockAudioDevice(SDL_AudioDeviceID dev);
  * \sa SDL_OpenAudio
  */
 extern DECLSPEC void SDLCALL SDL_CloseAudio(void);
+
+/**
+ * Use this function to shut down audio processing and close the audio device.
+ *
+ * The application should close open audio devices once they are no longer
+ * needed. Calling this function will wait until the device's audio callback
+ * is not running, release the audio hardware and then clean up internal
+ * state. No further audio will play from this device once this function
+ * returns.
+ *
+ * This function may block briefly while pending audio data is played by the
+ * hardware, so that applications don't drop the last buffer of data they
+ * supplied.
+ *
+ * The device ID is invalid as soon as the device is closed, and is eligible
+ * for reuse in a new SDL_OpenAudioDevice() call immediately.
+ *
+ * \param dev an audio device previously opened with SDL_OpenAudioDevice()
+ *
+ * \sa SDL_OpenAudioDevice
+ */
 extern DECLSPEC void SDLCALL SDL_CloseAudioDevice(SDL_AudioDeviceID dev);
 
 /* Ends C function definitions when using C++ */