docs: improve README file

[rlespinasse]

This improved README file:

• Expands the introduction to better explain what the action does.
• Adds a Why Use This Action? section to highlight its benefits.
• Includes a prerequisites section.
• Improves the structure and formatting for better readability.
• Provides more context for the usage examples.
• Enhances the parameters table with clearer notes.
• Add a section for additional information.