Add note about using MPF-MC to enable legacy sound pools

docs/install/0.80.md

@@ -59,4 +59,16 @@ The GMC manages all slides and widgets, so the `slides:` and `widgets:` config s
 
 The GMC manages all sound assets, so the `sound_system:` and `sounds:` config sections are deprecated. You can still reference sounds by filename directly, but if you want to specify specific settings for a sound or sound pool, use the `MPFSoundAsset` resource type in GMC.
 
-Audio channel groups have been renamed from "tracks" to "buses", so in your `sound_player:` config sections change `track: music` to `bus: music`.
+Audio channel groups have been renamed from "tracks" to "buses", so in your `sound_player:` config sections change `track: music` to `bus: music`.
+
+### Sound Pools
+
+The GMC includes support for sound pools using the `AudioStreamRandomizer` resource type. You can combine this sound pool with MPF-specific sound properties by creating an `MPFSoundAsset` resource and using an `AudioStreamRandomizer` as the stream.
+
+!!! warning "Using MPF Sound Pools"
+
+    If you have a large project with many `sound_pools:` defined in MPF configs, it is *possible* to continue using them until you migrate them to GMC. This hack is not officially supported, and may have unintended side-effects, so use with caution.
+
+    To enable sound pools in config files, you will need to install the legacy MPF-MC in your virtual environment with `pip install mpf-mc`. This will cause the MC to inject the sound pool configurations into MPF 0.80
+
+    **Note:** While MPF will manage the sound pools, it will not be able to map sound pool sound names to files configured in a `sounds:` config section (which is no longer supported). Your sound pools ***must** use the name of the sound file as the sound name or GMC will not be able to find the correct file.