broke readmes into finer-grained categories

integrations/README.md

@@ -5,3 +5,23 @@ This is a collection of example projects demonstrating how you can embed or inte
 
 For more support on these integrations take a look at the [docs/](../docs) folder. Specifically the [Shims](../docs/shims_zt_sdk.md) and [SDK API](../docs/zt_sdk.md) overviews. 
 Also stop by our [community section](https://www.zerotier.com/community/) for more in-depth discussion!
+
+***
+## Current Integrations
+
+### iOS
+ - [Embedding within an app](../docs/ios_zt_sdk.md)
+ - [Unity3D plugin](../docs/unity3d_ios_zt_sdk.md)
+
+### OSX
+ - [Embedding within an app](../docs/osx_zt_sdk.md) 
+ - [Dynamic-linking into an app/service at runtime](../docs/osx_zt_sdk.md) 
+ - [Unity3D plugin](../docs/unity3d_osx_zt_sdk.md) 
+
+### Linux
+ - [Dynamic-linking into an app/service at runtime](../docs/linux_zt_sdk.md) 
+ - [Using the SDK with Docker](../docs/docker_linux_zt_sdk.md)
+
+### Android
+ - [Embedding within an app](../docs/android_zt_sdk.md) 
+ - [Unity 3D plugin](../docs/unity3d_android_zt_sdk.md)