Fix links.

README.md

@@ -1,6 +1,6 @@
 ![Logo](src/icon.png)
 
-# Disposables [![Build status](https://github.com/StephenCleary/Disposables/workflows/Build/badge.svg)](https://github.com/StephenCleary/Disposables/actions?query=workflow%3ABuild) [![codecov](https://codecov.io/gh/StephenCleary/Disposables/branch/master/graph/badge.svg)](https://codecov.io/gh/StephenCleary/Disposables) [![NuGet version](https://badge.fury.io/nu/Nito.Disposables.svg)](https://www.nuget.org/packages/Nito.Disposables) [![API docs](https://img.shields.io/badge/API-dotnetapis-blue.svg)](http://dotnetapis.com/pkg/Nito.Disposables)
+# Disposables [![Build status](https://github.com/StephenCleary/Disposables/workflows/Build/badge.svg)](https://github.com/StephenCleary/Disposables/actions?query=workflow%3ABuild) [![codecov](https://codecov.io/gh/StephenCleary/Disposables/branch/main/graph/badge.svg)](https://codecov.io/gh/StephenCleary/Disposables) [![NuGet version](https://badge.fury.io/nu/Nito.Disposables.svg)](https://www.nuget.org/packages/Nito.Disposables) [![API docs](https://img.shields.io/badge/API-FuGet-blue.svg)](https://www.fuget.org/packages/Nito.Disposables)
 IDisposable helper types.
 
 # Main Types