chore: merge develop into master

[asalvi0]

This pull request introduces several significant updates to the Presidium codebase and documentation, focusing on modernizing dependencies, simplifying theme and template handling, and improving installation instructions. The most important changes are grouped below by theme.

Dependency and Tooling Updates:

• Added .github/dependabot.yml to enable automated dependency updates for Go modules, npm, Docker, and GitHub Actions, scheduled weekly.
• Updated Go version in go.mod to 1.23.0, added a toolchain specification, and refreshed indirect dependencies to newer versions.
• Changed GitHub Actions workflow runner from ubuntu-20.04 to ubuntu-latest for improved CI compatibility.

Theme and Template Refactoring:

• Removed the concept of "Theme" from site generation (pkg/domain/model/generator/model.go), consolidating site configuration to use only "Template" and adding a new BlogTemplate option. Also introduced a unique Uuid field for each site. (F211912dL8R8, [1] [2] [3] [4] [5] [6]

Documentation and Installation Improvements:

• Updated installation instructions across multiple documentation files to simplify Homebrew usage, removing the need to manually add the tap and switching to direct install commands for Presidium and related tools. [1] [2] [3] [4] [5] [6]
• Updated module imports in docs/config.yml and docs/go.mod to use presidium-styling-base and presidium-layouts-base instead of presidium-theme-website, reflecting refactored theme handling. [1] [2]

Minor Additions and Cleanups:

• Added a draft documentation page for scoped Presidium sites.
• Minor import ordering and cleanup in Go files for improved code hygiene. [1] [2]