added Copyright Notices

Author: LumePart

NOTICE

@@ -2,11 +2,14 @@ NOTICE
 ------
 This project includes the following third-party libraries:
 
-- **ffmpeg-go (https://github.com/u2takey/ffmpeg-go)**
+- ffmpeg-go (https://github.com/u2takey/ffmpeg-go)
   Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0).
+  Copyright (c) 2017 Karl Kroening
 
-- **goutubedl (https://github.com/wader/goutubedl)**
+- goutubedl (https://github.com/wader/goutubedl)
   Licensed under the MIT License.
+  Copyright (c) 2019 Mattias Wadman
 
-- **godotenv (https://github.com/joho/godotenv)**
-  Licensed under the MIT License.
+- godotenv (https://github.com/joho/godotenv)
+  Licensed under the MIT License.
+  Copyright (c) 2013 John Barton