docs: add missing Git long paths and PowerShell Core prerequisites

doc/devdocs/readme.md

@@ -83,6 +83,34 @@
 1. A local clone of the PowerToys repository
 1. Enable long paths in Windows (see [Enable Long Paths](https://docs.microsoft.com/windows/win32/fileio/maximum-file-path-limitation#enabling-long-paths-in-windows-10-version-1607-and-later) for details)
 
+#### Enable Git long paths (Windows)
+
+In addition to enabling long paths in Windows, Git must also be configured to support long paths.
+
+Run the following command in an elevated (Administrator) terminal:
+
+```powershell
+git config --system core.longpaths true
+
+
+
+```md
+#### PowerShell Core (pwsh)
+
+Some PowerToys build scripts rely on **PowerShell Core** (`pwsh`).
+
+Ensure that PowerShell Core is installed and available in your PATH.
+
+Installation instructions:
+https://learn.microsoft.com/powershell/
+
+Verify the installation by running:
+
+```powershell
+pwsh --version
+
+
+
 ### Install Visual Studio dependencies
 
 1. Open the `PowerToys.slnx` file.