update copyright notice with new text

Author: rcritz

README.markdown

@@ -1065,7 +1065,7 @@ The following copyright statement should be included at the top of every source
 file:
 
 ```swift
-/// Copyright (c) 2019 Razeware LLC
+/// Copyright (c) 2020 Razeware LLC
 /// 
 /// Permission is hereby granted, free of charge, to any person obtaining a copy
 /// of this software and associated documentation files (the "Software"), to deal
@@ -1085,6 +1085,10 @@ file:
 /// merger, publication, distribution, sublicensing, creation of derivative works,
 /// or sale is expressly withheld.
 /// 
+/// This project and source code may use libraries or frameworks that are
+/// released under various Open-Source licenses. Use of those libraries and
+/// frameworks are governed by their own individual licenses.
+///
 /// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 /// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 /// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE