Update to use Material for MkDocs Insiders

[Marius Storhaug (MariusStorhaug)]

Description

This pull request updates the .github/workflows/Docs.yml file to improve the installation process for mkdocs-material and its plugins. The most important change is the switch to using the insider version of mkdocs-material with authentication.

• Fixes 🩹 [Patch]: Update to use Material for MkDocs Insiders #15

Workflow improvements:

• Install mkdocs-material step: Updated to install the insider version of mkdocs-material using a GitHub token (GH_TOKEN) for authentication. This ensures access to the premium features of the package.
• Plugin installation: Adjusted the installation sequence to separate the mkdocs-material insider installation from the other plugins.

Type of change

• 📖 [Docs]
• 🪲 [Fix]
• 🩹 [Patch]
• ⚠️ [Security fix]
• 🚀 [Feature]
• 🌟 [Breaking change]

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas