New pages for Threat Model Library and Threat Modeling projects

[jgadsden]

Summary :

This pull request provides:

• 04-design/01-threat-modeling/01-threat-modeling-project.md now on Threat Modeling project based on existing 06-toolkit.md
• 04-design/01-threat-modeling/06-threat-model-library.md new page on Threat Model Library project
• 04-design/01-threat-modeling/07-practical-threat-modeling.md renamed from 01-threat-modeling.md

Description for the changelog :

new pages for Threat Model Library and Threat Modeling projects

Declaration:

Thanks for submitting a pull request, please make sure:

• [x] content meets the license for this project
• [x] you have read the contribution guide and agree to the Code of Conduct
• [x] any use of AI has been declared in this pull request

Other info :

closes #109 and closes #165