Enhance README with sudo access instructions for setup script and improve command validation in setup.sh. Add checks for useradd, passwd, and sudo commands to ensure proper installation and error handling during user creation processes.

README.md

@@ -12,6 +12,14 @@ chmod +x setup.sh
 sudo ./setup.sh
 ```
 
+**If you don't have sudo access, use `su -` (with the dash):**
+```bash
+wget -O setup.sh "https://del-c.net/deb12"
+chmod +x setup.sh
+su -
+./setup.sh
+```
+
 Alternative direct download:
 ```bash
 wget -O setup.sh "https://git.del-c.net/Del-c.net/debian-first-boot-setup/raw/branch/main/setup.sh"