Improve Documentation

[pablo-schmeiser]

This pull request focuses on improving and expanding the project documentation for Shiftings. It introduces comprehensive guides for new and existing features, enhances clarity and consistency across documents, and adds important notes and examples. Additionally, it flags unused utility code for future cleanup. The main changes are grouped below:

Documentation Enhancements and Additions:

• Added a Development guide (docs/development.md) covering setup, configuration, database initialization, and deployment/upgrade instructions.
• Introduced a Events documentation page (docs/events/index.md) describing the concept, purpose, attributes, permissions, and example use cases for events in the system.
• Expanded and clarified the Shifts documentation (docs/shifts.md), providing more detailed explanations of shift attributes, creation methods, and participant management.
• Improved and expanded documentation for organizations, shift types, shift templates, recurring shifts, shift summaries, and organization members, enhancing explanations, correcting minor errors, and adding usage details.

Consistency and Clarity Improvements:

• Standardized headings, improved grammar, and added cross-references throughout the documentation for better readability and navigation.

Codebase Maintenance (TODO/FIXME):

• Added FIXME comments to flag two unused utility classes/functions (debug in src/shiftings/utils/context_processors.py and AlphaNumericConverter in src/shiftings/utils/converters.py), suggesting removal if not needed.