Add project documentation and architecture details

- Create .gitignore to exclude specific project files and directories.
- Add CONTRIBUTING.md with guidelines for contributing to the project.
- Update README.md to reflect changes in usage section and contact information.
- Introduce 08_concepts.md outlining cross-cutting concepts in the architecture.
- Add 02_data_model.md detailing the data model and relationships.
- Implement 03_security.md to describe security measures and practices.
- Establish 08_ui_design.md for user interface design principles.
- Document quality requirements in 10_quality_requirements.md.
- Identify risks and technical debts in 11_technical_risks.md.
- Create a glossary in 12_glossary.md for project-specific terms.
- Include about-arc42.md to explain the arc42 documentation template.
- Define price calculation variables and formula in price_calculation.md.
- Introduce ADR template in adr.md for documenting architecture decisions.

README.md

@@ -12,7 +12,7 @@ Welcome to the Calminer documentation! This guide provides an overview of the Ca
     - [Key Features](#key-features)
   - [Architecture](#architecture)
   - [Installation](#installation)
-  - [Usage](#usage)
+  - [User Guide](#user-guide)
   - [API Reference](#api-reference)
   - [Contributing](#contributing)
   - [FAQ](#faq)
@@ -50,9 +50,9 @@ We use arc42 as a template for documenting our architecture. Please see [Archite
 
 Instructions for installing Calminer can be found in the [Installation](admin/installation.md) section of the documentation. Follow the steps outlined there to set up Calminer on your system.
 
-## Usage
+## User Guide
 
-Usage instructions for Calminer can be found in the [Usage](userguide/README.md) section of the documentation. This includes guidelines and examples for using Calminer effectively.
+Usage instructions for Calminer can be found in the [User Guide](userguide/README.md) section of the documentation. This includes guidelines and examples for using Calminer effectively.
 
 ## API Reference
 
@@ -76,8 +76,10 @@ This project is licensed under the GNU General Public License v3.0. See the [LIC
 
 ## Contact
 
-For support or inquiries, please contact the Calminer team at [calminer@allucanget.biz](mailto:calminer@allucanget.biz).
+For support or inquiries, please contact the Calminer team at <calminer@allucanget.biz>.
 
 ## Acknowledgements
 
 We would like to thank all contributors and third-party resources that have helped make Calminer possible.
+
+This Architecture Documentation is based on the [arc42 template](architecture/about-arc42.md).