Add Search Functionality to DevEx Documentation

[danbaruka]

Problem statement

The DevEx documentation currently does not provide any in-site search functionality. As the documentation continues to grow, developers and contributors must rely on manual navigation, which increases onboarding friction and slows down information discovery.

Proposed solution

Introduce a searchable documentation experience by:

• Integrating a documentation search solution (e.g. Algolia DocSearch, Meilisearch, or equivalent)
• Indexing DevEx documentation content
• Adding a global search input in the header or sidebar
• Ensuring search results link directly to relevant pages or sections

Scope and impact

Scope

• DevEx documentation hosted on https://devex.intersectmbo.org
• Documentation discovery and navigation
• Search UI integration and indexing configuration

Impact

• Faster access to relevant information
• Reduced onboarding friction for new contributors
• Lower support overhead for maintainers
• Improved overall developer experience

Checks

• I searched existing issues and discussions
• This is a feature/enhancement request (not a question or doc issue)