Index HOCON config data in search

[valencik]

Blog posts and events contain all sorts of nice metadata in their HOCON configs:

typelevel.github.com/src/blog/typelevel-org-built-with-typelevel.md

Lines 1 to 5 in dee9276

	{%
	author: [${armanbilge}, ${valencik}]
	date: "2026-02-18"
	tags: [community]
	%}

If we're able to expose this data to protosearch at indexing time then we can enable filtering by author / tag / etc in search.