Update oneshot installation to clone repository locally

- Modified install.ps1 to clone git-workshop repository to ~/git-workshop
- Added option to remove existing directory before cloning
- Updated documentation to reflect the new behavior
- Now provides complete setup: install tools + clone repo in one command
- Similar to Scoop's get.scoop.sh installation pattern

README.md

@@ -82,12 +82,17 @@ Then run scripts using:
 **Quick Automated Installation (Windows 11):**
 
 **Option 1: Oneshot Installation (Recommended)**
-Download and run everything in one command:
+Download, install prerequisites, and clone the repository in one command:
 
 ```powershell
 irm https://git.frod.dk/floppydiscen/git-workshop/raw/branch/main/install.ps1 | iex
 ```
 
+This will:
+- Install PowerShell 7, Git 2.23+, and Visual Studio Code
+- Clone the git-workshop repository to `~/git-workshop`
+- Leave you ready to start the first module
+
 **Option 2: Local Installation**
 Clone the repository first, then run: