Remove linux support doc

Author: JoeRobich

docs/C#-Extension-support-for-new-Linux-Distros-with-.NET-Core.md

@@ -6,7 +6,6 @@
 * [Installing without internet connectivity](./Installing-without-Internet-connectivity.md)
 * [How to run and debug unit tests](./How-to-run-and-debug-unit-tests.md)
 * [Troubleshooting: 'The .NET Core SDK cannot be located.' errors](./Troubleshooting-'The-.NET-Core-SDK-cannot-be-located.'-errors.md)
-* [Linux Support](./C#-Extension-support-for-new-Linux-Distros-with-.NET-Core.md)
 
 **Debugger**