Update README.md

Author: robertmuehsig

README.md

@@ -134,15 +134,23 @@ In this YouTube video, we show you how you can create a new project, use the Ele
 Here you need the Electron.NET CLI too. Type following command in your ASP.NET Core folder:
 
 ```
-    dotnet electronize build
+    dotnet electronize build /target win
 ```
 
-In your default setting we just build the application for the OS you are running (Windows builds Windows, macOS builds macOS etc.), but this can be changed with:
+There are additional platforms available:
 
 ```
-    dotnet electronize build win
-    dotnet electronize build osx
-    dotnet electronize build linux
+    dotnet electronize build /target win
+    dotnet electronize build /target osx
+    dotnet electronize build /target linux
+```
+
+Those three "default" targets will produce x64 packages for those platforms.
+
+For certain NuGet packages or certain scenarios you may want to build a pure x86 application. To support those things you can define the desired [.NET Core runtime](https://docs.microsoft.com/en-us/dotnet/core/rid-catalog), the [electron platform](https://github.com/electron-userland/electron-packager/blob/master/docs/api.md#platform) and [electron architecture](https://github.com/electron-userland/electron-packager/blob/master/docs/api.md#arch) like this:
+
+```
+    dotnet electronize build build /target custom win7-x86;win32 /electron-arch ia32 
 ```
 
 The end result should be an electron app under your __/bin/desktop__ folder.