[SPARKNLP-1015] Restructuring Readme and Documentation

[danilojsl]

Description

This PR focuses on restructuring the README and documentation to enhance clarity, organization, and accessibility.

Motivation and Context

• Improved User Experience: Enhanced readability and navigability make it easier for users to find information.
• Better Maintenance: Organized structure simplifies future updates and maintenance.
• Increased Accessibility: Clear and comprehensive documentation ensures that users at all levels can understand and utilize spark-nlp effectively.

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Code improvements with no or little impact
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING page.
• I have added tests to cover my changes.
• All new and existing tests passed.