docs: add getting started section with screenshots

Add step-by-step instructions for using the template with screenshots
showing the "Use this template" button and repository creation page.

Author: arcangelo7

.github/images/create_new_repo.png

@@ -2,6 +2,18 @@
 
 A template for creating Python packages with UV dependency management, pytest testing, semantic-release versioning, and optional Astro Starlight documentation.
 
+## Getting started
+
+1. Click the **Use this template** button on GitHub:
+
+   !["Use this template" button](.github/images/use_this_template.png)
+
+2. Select **Create a new repository**, fill in the repository name, and click **Create repository**:
+
+   !["Create a new repository" page](.github/images/create_new_repo.png)
+
+3. Clone your new repository and continue with the setup below.
+
 ## Prerequisites
 
 - Python 3.10+

.github/images/use_this_template.png

@@ -288,6 +288,11 @@ def main() -> int:
     for filepath in setup_files:
         if filepath.exists():
             filepath.unlink()
+
+    images_dir = SCRIPT_DIR / ".github" / "images"
+    if images_dir.exists():
+        shutil.rmtree(images_dir)
+
     print_success("Setup files removed")
 
     print_header("Setup complete")