Docs search is broken on sub-pages

[jobara]

Describe the bug

When searching from the "Tutorials" or "Components" sub-pages of the Infusion Documentation site, the server returns a 404. It seems this might be a relative pathing issue, as these pages are hosted from subdirectories.

URL for a successful search:

• https://docs.fluidproject.org/infusion/development/search.html?qs=%22test%22

URLs for unsuccessful searches:

• https://docs.fluidproject.org/infusion/development/tutorial-developerIntroduction/search.html?qs=%22test%22
• https://docs.fluidproject.org/infusion/development/to-do/search.html?qs=%22test%22

To reproduce

Steps to reproduce the behavior:

1. Go to the Infusion Docs site
2. Click on "Tutorials" or "Components" on the top-right of the page
3. Click on one of the topics along the left-side menu (e.g. "Opening Remarks" in Tutorials or "Pager" in Components)
4. Enter a search term in the search bar and hit enter to run the search

Expected behavior

The search results page is displayed with the appropriate results

Additional context or notes

Originally filed as FLUID-6501

[jobara]

Resolved with #263