update pre-release package badge link (#2539)

Author: WeihanLi

README.md

@@ -13,6 +13,6 @@ MyGet Pre-release feed: https://www.myget.org/gallery/stackoverflow
 
 | Package | NuGet Stable | NuGet Pre-release | Downloads | MyGet |
 | ------- | ------------ | ----------------- | --------- | ----- |
-| [StackExchange.Redis](https://www.nuget.org/packages/StackExchange.Redis/) | [![StackExchange.Redis](https://img.shields.io/nuget/v/StackExchange.Redis.svg)](https://www.nuget.org/packages/StackExchange.Redis/) | [![StackExchange.Redis](https://img.shields.io/nuget/vpre/StackExchange.Redis.svg)](https://www.nuget.org/packages/StackExchange.Redis/) | [![StackExchange.Redis](https://img.shields.io/nuget/dt/StackExchange.Redis.svg)](https://www.nuget.org/packages/StackExchange.Redis/) | [![StackExchange.Redis MyGet](https://img.shields.io/myget/stackoverflow/vpre/StackExchange.Redis.svg)](https://www.myget.org/feed/stackoverflow/package/nuget/StackExchange.Redis) |
+| [StackExchange.Redis](https://www.nuget.org/packages/StackExchange.Redis/) | [![StackExchange.Redis](https://img.shields.io/nuget/v/StackExchange.Redis.svg)](https://www.nuget.org/packages/StackExchange.Redis/) | [![StackExchange.Redis](https://img.shields.io/nuget/vpre/StackExchange.Redis.svg)](https://www.nuget.org/packages/StackExchange.Redis/absoluteLatest) | [![StackExchange.Redis](https://img.shields.io/nuget/dt/StackExchange.Redis.svg)](https://www.nuget.org/packages/StackExchange.Redis/) | [![StackExchange.Redis MyGet](https://img.shields.io/myget/stackoverflow/vpre/StackExchange.Redis.svg)](https://www.myget.org/feed/stackoverflow/package/nuget/StackExchange.Redis) |
 
-Release notes at: https://stackexchange.github.io/StackExchange.Redis/ReleaseNotes
+Release notes at: https://stackexchange.github.io/StackExchange.Redis/ReleaseNotes