Document r_glDebugContext in Configuration.md; tiny fix in settings menu

Configuration.md

@@ -18,7 +18,7 @@ useful commandline arguments, for example how to tell dhewm3 where the game data
 
 When built with [Dear ImGui](https://github.com/ocornut/imgui) integration (which is the default
 when using SDL2), dhewm3 has an advanced settings menu with many settings that the main menu doesn't
-offer, including a *Control BIndings* menu that supports as many keys per command as you want and is
+offer, including a *Control Bindings* menu that supports as many keys per command as you want and is
 fully navigable with keyboard or gamepad (or mouse, of course).
 
 Unless you have already bound your `F10` key to something else, it will open this menu.  
@@ -218,6 +218,8 @@ This can be configured with the following CVars:
 - `r_useCarmacksReverse` Use Z-Fail ("Carmack's Reverse") when rendering shadows (default `1`)
 - `r_useStencilOpSeparate` Use glStencilOpSeparate() (if available) when rendering shadow (default `1`)
 - `r_scaleMenusTo43` Render full-screen menus in 4:3 by adding black bars on the left/right if necessary (default `1`)
+- `r_glDebugContext` Enable OpenGL debug context and printing warnings/errors from the graphics driver.  
+  Changing that CVar requires a `vid_restart` (or set it as startup argument)
 
 - `s_alReverbGain` reduce strength of OpenAL (EAX-like) EFX reverb effects, `0.0` - `1.0` (default `0.5`)
 - `s_alHRTF` Enable [HRTF](https://en.wikipedia.org/w/index.php?title=Head-related_transfer_function)

neo/framework/Dhewm3SettingsMenu.cpp

@@ -1971,6 +1971,7 @@ static float audioMenuItemOffset = 0.0f;
 static void InitAudioOptionsMenu()
 {
 	alDevices.SetNum( 0, false );
+	selAlDevice = 0; // default device (another one might be set in loop below)
 
 	const char* device = idSoundSystemLocal::s_device.GetString();
 	if ( *device == '\0' || idStr::Cmp( device, "default" ) == 0 ) {