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

* Updated certain Oban queues to have a configurable limit

* Updated README

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"]))