Add HMI Application Custom Sounds Best Practice

config.json

@@ -11,6 +11,9 @@
         },
         {
             "name": "Graphics"
+   	    },
+        {
+            "name": "HMI Application Custom Sounds"
         },
         {
             "name": "Languages"

docs/HMI Application Custom Sounds/index.md

@@ -0,0 +1,12 @@
+## HMI Application Custom Sounds
+
+#### Background
+This topic was brought forward by a SmartDeviceLink Consortium (SDLC) Steering Committee representative via proposal [SDL 0103](https://github.com/smartdevicelink/sdl_evolution/blob/master/proposals/0103-ApplicationCustomSounds.md).  The proposed solution described within the proposal was accepted by the Steering Committee, as noted in the [review issue](https://github.com/smartdevicelink/sdl_evolution/issues/308).  This document serves to capture the best practice decided upon by the SDLC Steering Committee.
+
+#### Best Practice
+**Application Partners shall control all in-vehicle noises.**
+
+OEMs will not always know what is being projected to the head unit; this will make noise flags, noise triggers, and noise accuracy difficult to handle on the OEM side.  This makes Application Partner control advantageous.
+
+#### Additional Information
+Additional information regarding the motivation for this best practice, alternatives considered, etc. can be found in the proposal [SDL 0103](https://github.com/smartdevicelink/sdl_evolution/blob/master/proposals/0103-ApplicationCustomSounds.md).