Add @PowerShell (EN)

Author: RiikkaDream

src/content/3/en/part3b.md

@@ -392,7 +392,7 @@ The script looks like this
 ##### Note for Windows users
 Note that the standard shell commands in `build:ui` do not natively work in Windows. Powershell in Windows works differently, in which case the script could be written as
 ```json
-"build:ui": "Remove-Item -Recurse -Force build && cd ../frontend && npm run build && Copy-Item build -Recurse ../backend",
+"build:ui": "@powershell Remove-Item -Recurse -Force build && cd ../frontend && npm run build && @powershell Copy-Item build -Recurse ../backend",
 ```
   
 If the script does not work on Windows, confirm that you are using Powershell and not Command Prompt. If you have installed Git Bash or another Linux-like terminal, you may be able to run Linux-like commands on Windows as well.