docs(search): Algolia troubleshooting section for index configuration problems

[slorber]

Motivation

Many Docusaurus sites using Algolia DocSearch encounter index configuration problems.

This is a bit nasty because:

• I think the Algolia team creates the initial crawler config and they may make mistakes
• Docusaurus sites upgrade from v1 to v2/v3, with significant config changes
• Changing the crawler config initialIndexSettings is not automatically applied to the index
• It's easier to delete/recreate the index from scratch on config change

For that reason, let's write more information on our docs so that we receive fewer support requests on GitHub or Discord.

• https://deploy-preview-10056--docusaurus-2.netlify.app/docs/search#algolia-index-configuration
• https://deploy-preview-10056--docusaurus-2.netlify.app/docs/search#algolia-troubleshooting

Related issues/PRs

#10050

#9200

#10007

... and many others

[netlify]

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[github-actions]

⚡️ Lighthouse report for the deploy preview of this PR

URL	Performance	Accessibility	Best Practices	SEO	PWA	Report
/	🟠 67	🟢 98	🟢 96	🟢 100	🟠 88	Report
/docs/installation	🟠 64	🟢 96	🟢 100	🟢 100	🟠 88	Report
/docs/category/getting-started	🟠 74	🟢 100	🟢 100	🟢 90	🟠 88	Report
/blog	🟠 70	🟢 100	🟢 100	🟢 90	🟠 88	Report
/blog/preparing-your-site-for-docusaurus-v3	🟠 59	🟢 96	🟢 100	🟢 100	🟠 88	Report
/blog/tags/release	🟠 66	🟢 100	🟢 100	🟠 80	🟠 88	Report
/blog/tags	🟠 73	🟢 100	🟢 100	🟢 90	🟠 88	Report

[github-actions]

Size Change: 0 B

Total Size: 1.59 MB

ℹ️ View Unchanged

Filename	Size
website/.docusaurus/codeTranslations.json	2 B
website/.docusaurus/docusaurus.config.mjs	26.7 kB
website/.docusaurus/globalData.json	91.2 kB
website/.docusaurus/i18n.json	930 B
website/.docusaurus/registry.js	247 kB
website/.docusaurus/routes.js	156 kB
website/.docusaurus/routesChunkNames.json	109 kB
website/.docusaurus/site-metadata.json	2.17 kB
website/build/assets/css/styles.********.css	113 kB
website/build/assets/js/main.********.js	808 kB
website/build/index.html	38 kB

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[slorber]

Hey @shortcuts, will merge now, but feel free to review and submit a PR if you think any of this is incorrect