Update README.md for .NET 8 SDK update

README.md

@@ -147,7 +147,9 @@ For instructions on using this tutorial, see [Instructions](https://github.com/d
    2. .NET Core cross-platform development
    3. Visual Studio extension development
 2. Clone this repository
-3. Install .NET SDK version specified in `.\global.json` with `"dotnet":` from [here](https://dotnet.microsoft.com/download/dotnet-core).
+3. Install .NET SDK version specified in `.\global.json` with `"dotnet":`
+   - Currently, the repository requires the .NET 8 SDK, for which the installer isn't yet published in [dotnet.microsoft.com](https://dotnet.microsoft.com/download/dotnet-core).
+   - To install the .NET 8 SDK, see [dotnet/installer](https://github.com/dotnet/installer#table).
 4. Open a command prompt and go to the directory of the Roslyn Analyzer Repo
 5. Run the restore and build command: `build.cmd`(in the command prompt) or `.\build.cmd`(in PowerShell).
 6. Execute tests: `test.cmd` (in the command prompt) or `.\test.cmd` (in PowerShell).