Update knn-search.asciidoc

[giladgal]

The recommendation regarding performing heavy indexing with search is probably worded a bit too extremely

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[github-actions]

Documentation preview:

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[elasticsearchmachine]

Pinging @elastic/es-docs (Team:Docs)

[elasticsearchmachine]

Pinging @elastic/es-search (Team:Search)

[shainaraskas]

I think you also need to soften the language on line 140 to match this sentiment.

[elasticsearchmachine]

Pinging @elastic/es-search-relevance (Team:Search Relevance)

[leemthompo]

Important

Elastic documentation is migrating to Markdown for version 9.0+. See the migration guide for details.

ℹ️ What's happening?

• Starting January 29, we will start closing all unmerged documentation PRs targeting main/master
• We're migrating from AsciiDoc to Markdown for 9.0+
• 9.0 docs will be frozen from January 29 until February 20 2024
• NOTE: PRs that include both code and documentation changes will remain open

What do I need to do?

For <=8.x docs:

1. Rebase your PR to target the relevant 8.x branch instead
2. The content can remain in AsciiDoc format

For 9.0+ docs:

Option 1:

• Draft docs in Markdown
• Once migration freeze ends, find the relevant page in the new docs system and use the edit options to submit your changes

Option 2:

• Open an issue in elastic/docs-content

💡 Need help?

1. For Elasticians: Ask in #docs Slack channel
2. For external contributors: Open an issue in elastic/docs-content