Support Pagefind for search

[veselosky]

Pagefind is a tool that adds full text search for static sites. It pre-generates an index and includes search box that loads partial chunks of the index to conduct searches in the browser with JavaScript. Pagefind indexes static HTML files after they are generated. It can be configured by including certain markup in pages.

• Create an include component with the search UI (see the docs).
• Create a new header block that includes the search UI
• Modify the default templates to add the data-pagefind-body attribute to the main content block for articles and pages, and the precontent block for sections and home pages.
• Add data-pagefind-meta attributes to identify the title, image, image_alt, section (for articles) and updated date.
• Add data-pagefind-filter attributes to allow filtering by author, tags, and section.