docs(readme): add features, installation, and troubleshooting sections

[robinlahtinen]

This pull request significantly expands and improves the README.md documentation for the @semantic-org/astro-lit package. The new documentation provides clearer installation and usage instructions, highlights key features, and adds troubleshooting guidance for common issues. It also includes badges for NPM version, downloads, and license for better project visibility.

Documentation improvements:

• Added project badges (NPM version, downloads, license) to the top of the README.md for enhanced visibility.
• Expanded installation instructions, including prerequisites and step-by-step setup for different package managers.
• Added detailed usage examples for creating and importing Lit components, using third-party Lit components, and enabling client-side hydration with Astro directives.
• Included instructions for enabling and using experimental decorators in TypeScript with Lit.

Troubleshooting and contribution guidance:

• Added a troubleshooting section covering issues like browser global interference, component updates in development, and strict package manager errors (with solutions).
• Provided clear guidelines for contributing, including how to report bugs and submit pull requests.

Fixes: #1

[daniel-sc]

when I try this, it is not possible to combine this with client:load. On the other hand, when using <SbbButton..> I get "Astro Type Erros" when setting attributes/properties. Don't know if I miss something here..

[jlukic]

Thank you for your contribution!