Better document MUSIC_DIRECTORY_PATH

deploy/env.prod.sample

@@ -113,4 +113,4 @@ RAVEN_DSN=https://44332e9fdd3d42879c7d35bf8562c6a4:0062dc16a22b41679cd5765e5342f
 # You can safely leave those settings uncommented if you don't plan to use
 # in place imports.
 # MUSIC_DIRECTORY_PATH=
-# MUSIC_DIRECTORY_SERVE_PATH=
+# MUSIC_DIRECTORY_SERVE_PATH=  # docker-only

deploy/nginx.conf

@@ -83,6 +83,7 @@ server {
         # this is an internal location that is used to serve
         # audio files once correct permission / authentication
         # has been checked on API side
+        # Set this to the same value as your MUSIC_DIRECTORY_PATH setting
         internal;
         alias   /srv/funkwhale/data/music;
     }