Search v2

We need to implement our next version of Janis search functionality. The current version only searches by page title against a json file. It's time for us to upgrade to a new search service like Google or Algolia.

This is primarily for searching the official documents list, but we should construct the API in such a way that this functionality could be used anymore, including the main search page.

Requirements:
- [ ] Search against fields besides "title" (steps, description, body, etc.; these fields will be different depending on the content type)
- [ ] Highlight keyword matches in `page description` (if available)
- [ ] Filter based on date
- [ ] Before, After
- [ ] Or a range
- [ ] Search by keyword against a subset of pages (like within an official document list)
- [ ] Highlight keyword matches in `page description` (if available)

Previous Discussion:
https://github.com/cityofaustin/techstack/issues/4113
https://github.com/cityofaustin/techstack/issues/4290

Google API docs:
https://developers.google.com/custom-search/v1/using_rest
https://cse.google.com/cse?cx=866a37450f23477e4