Documentation update, particularly on metrics

[ThijsVroegh]

This pull request includes several updates to the documentation of the Unraphael project, including improvements to the contributing guidelines, credits, project description, and detailed steps for image clustering. The most important changes are categorized into updates to contributing guidelines, credits and contact information, project description, and image clustering documentation.

Updates to Contributing Guidelines:

• docs/CONTRIBUTING.md: Updated the path reference for the contributing guidelines.

Credits and Contact Information:

• docs/credits.md: Added a detailed credits and contact information section, including general inquiries, technical support, collaboration opportunities, and social media links.

Project Description:

• docs/index.md: Added a comprehensive description of the Unraphael tool, highlighting its purpose, features, and applicability beyond the study of Raphael's paintings.

Image Clustering Documentation:

• docs/steps/clustering.md: Enhanced the documentation for the image clustering process, detailing key features, preprocessing steps, clustering methods, and evaluation metrics. This includes a structured workflow for displaying, equalizing, aligning, and clustering images, as well as viewing cluster results and performance metrics. [1] [2] [3] [4]

Navigation Updates:

• mkdocs.yml: Updated the navigation structure to include the new credits page and reorganized the tutorials section.

[stefsmeets]

This does not render as a link

Suggested change

	- **Website**: https://www.uu.nl/medewerkers/LCostiner
	- **Website**: [https://www.uu.nl/medewerkers/LCostiner](https://www.uu.nl/medewerkers/LCostiner)

[stefsmeets]

Looks good to me, I fixed a link and have a minor comment.