Server v4 (#370)

* refactoring-1

introduced pipelines and abstracted download process.go in Downloader interface

* migrated to boltdb from sqlite + session files

* refactoring: config struct & pipelines

* added js runtime for yt-dlp

* updated dockerfile

* added external js runtime, metadata scraping refactor

* updated Dockerfile

* fixed env propagation in docker

* updated package name to v4

* updated readme and cd

.vscode/launch.json

@@ -9,7 +9,11 @@
             "type": "go",
             "request": "launch",
             "mode": "debug",
-            "program": "main.go"
+            "program": "main.go",
+            "args": [
+                "--conf",
+                "./config.yml"
+            ]
         },
         {
             "type": "chrome",