search: rank summary matches before content matches

This boosts the search ranking of pages that match a search term in
their summary field over those that only match in the page content.

Also: add an explicit page summary for a page to test that it now ranks
for the term "FAQ" (which was previously absent from the page content).

This will not be testable before the change is made to the search index,
which only happens after CL submission. The impact of this change being
incorrect should be close to zero, as nothing is being removed from the
search results. The only change could be some subtle results reordering,
and an updated search-results-page snippet for the FAQ page.

After this change is made, and its effect can be observed behaving as
expected on the live site, an issue tracking the lack of explicit page
summaries will be opened.

Fixes cue-lang/docs-and-content#194.

Signed-off-by: Jonathan Matthews <[email protected]>
Change-Id: Ic58451a879839e1748c71d5a8b7413d1a5d56107
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cuelang.org/+/1208424
Reviewed-by: Paul Jolly <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>

content/docs/concept/faq/new-modules-vs-old-modules/en.md

@@ -2,6 +2,10 @@
 title: New modules vs old modules
 tags: [modules]
 toc_hide: false
+summary: |
+  Frequently Asked Questions (FAQ) about the differences between CUE's old
+  modules implementation and its new modules implementation that became the
+  default with CUE v0.9.0.
 ---
 
 The [v0.9.0](/releases/v0.9.0) release of CUE

hugo/algolia-settings.js

@@ -20,7 +20,7 @@ const index = client.initIndex(indexName);
 
 index.setSettings({
     queryLanguages: ['en'],
-    searchableAttributes: ['title', 'content', 'summary', 'tags', 'contentType', 'authors'],
+    searchableAttributes: ['title', 'summary', 'content', 'tags', 'contentType', 'authors'],
     attributesForFaceting: ['tags', 'contentType', 'authors'],
     distinct: true,
     attributeForDistinct: 'link',

hugo/content/en/docs/concept/faq/new-modules-vs-old-modules/index.md

@@ -2,6 +2,10 @@
 title: New modules vs old modules
 tags: [modules]
 toc_hide: false
+summary: |
+  Frequently Asked Questions (FAQ) about the differences between CUE's old
+  modules implementation and its new modules implementation that became the
+  default with CUE v0.9.0.
 ---
 
 The [v0.9.0](/releases/v0.9.0) release of CUE