[Enhancement] Support specifying count of yt-dlp workers per-queue (#355)

* Updated certain Oban queues to have a configurable limit

* Updated README

config/config.exs

@@ -57,16 +57,6 @@ config :pinchflat, Oban,
        {"0 1 * * *", Pinchflat.Downloading.MediaRetentionWorker},
        {"0 2 * * *", Pinchflat.Downloading.MediaQualityUpgradeWorker}
      ]}
-  ],
-  # TODO: consider making this an env var or something?
-  queues: [
-    default: 10,
-    fast_indexing: 6,
-    media_indexing: 2,
-    media_collection_indexing: 2,
-    media_fetching: 2,
-    local_data: 8,
-    remote_metadata: 4
   ]
 
 # Configures the mailer

config/runtime.exs

@@ -40,6 +40,20 @@ config :pinchflat, Pinchflat.Repo,
     Path.join([:code.priv_dir(:pinchflat), "repo", "extensions", "sqlean-linux-#{system_arch}", "sqlean"])
   ]
 
+# Some users may want to increase the number of workers that use yt-dlp to improve speeds
+# Others may want to decrease the number of these workers to lessen the chance of an IP ban
+{yt_dlp_worker_count, _} = Integer.parse(System.get_env("YT_DLP_WORKER_CONCURRENCY", "2"))
+
+config :pinchflat, Oban,
+  queues: [
+    default: 10,
+    fast_indexing: 6,
+    media_collection_indexing: yt_dlp_worker_count,
+    media_fetching: yt_dlp_worker_count,
+    remote_metadata: yt_dlp_worker_count,
+    local_data: 8
+  ]
+
 if config_env() == :prod do
   config_path = "/config"
   db_path = System.get_env("DATABASE_PATH", Path.join([config_path, "db", "pinchflat.db"]))