✨ feat: allow showcasing featured projects on homepage

[welpo]

Summary

Allows showcasing a selection of n projects on the home page.

Related issue

Resolves #291.

Changes

To use this option, set the projects_path on your content/_index.md file:

[extra]
projects_path = "projects/_index.md"

It's possible to set the maximum number of projects with max_projects. By default, projects are shown after the posts. To reverse the sorting (show projects first), set show_projects_first = true.

• Moves the logic to list blog posts to a partial html file, similar to the new listing projects html.
• Adds some CSS.
• Adds two i18n strings.

Accessibility

Uses semantic HTML and styling from the Projects section; keyboard navigation, colour contrast etc. was already OK.

Screenshots

Type of change

• [ ] Bug fix (fixes an issue without altering functionality)
• [X] New feature (adds non-breaking functionality)
• [ ] Breaking change (alters existing functionality)
• [ ] UI/UX improvement (enhances user interface without altering functionality)
• [ ] Refactor (improves code quality without altering functionality)
• [ ] Documentation update
• [ ] Other (please describe below)

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Checklist

• [X] I have verified the accessibility of my changes
• [X] I have tested all possible scenarios for this change
• [ ] I have updated theme.toml with a sane default for the feature
• [X] I have made corresponding changes to the documentation:
  • [ ] Updated config.toml comments
  • [ ] Updated theme.toml comments
  • [X] Updated "Mastering tabi" post in English
  • [X] (Optional) Updated "Mastering tabi" post in Spanish
  • [X] (Optional) Updated "Mastering tabi" post in Catalan