feat: update supported Python versions to 3.10-3.13

- Update CI/CD matrix to test Python 3.10, 3.11, 3.12, 3.13
- Remove support for Python 3.8 and 3.9 (EOL/deprecated)
- Update documentation to reflect minimum Python 3.10+ requirement
- Dockerfile already uses Python 3.13 as latest stable version

BREAKING CHANGE: Minimum Python version is now 3.10

Author: michaelsstuff

.github/workflows/ci-cd.yml

@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.9, '3.10', 3.11, 3.12]
+        python-version: ['3.10', 3.11, 3.12, 3.13]
 
     steps:
     - name: Checkout code

README.md

@@ -157,13 +157,13 @@ with multiple lines[/quote]
 ## Installation & Dependencies
 
 ### Python Requirements
-- **Python 3.8+**: Core runtime
+- **Python 3.10+**: Core runtime
 - **click**: Command-line interface framework
 - **markdown**: Markdown parsing (used for validation)
 
 ### Docker Image
 The Docker image is built on Alpine Linux for minimal size and includes:
-- Python 3.11 runtime
+- Python 3.13 runtime
 - All required dependencies
 - Non-root user execution
 - Optimized for production use