Add search functionality (at least across Markdown files)

[Arcank]

Steps to repro:

• Have several md files for documentation.
• Try to search across the pages.

What happens:

• Not possible. You have to be on the markdown file to then use the browser search feature.

What should happen:

• Website-like docs/ folders should be able to feature a search box (just like we can show a nav bar for example).