Update title on custom ILM policy tutorial - example-index-lifecycle-policy.asciidoc

[rseldner]

Updated title and some wording to align with the updated guidance to NOT customize the built in policies.

[github-actions]

Documentation preview:

• ✨ Changed pages

[elasticsearchmachine]

@rseldner please enable the option "Allow edits and access to secrets by maintainers" on your PR. For more information, see the documentation.

[elasticsearchmachine]

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

[elasticsearchmachine]

Pinging @elastic/es-data-management (Team:Data Management)

[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

[elasticsearchmachine]

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

[shainaraskas]

opened an issue to address this and some of the other tutorial positioning in the new repo elastic/docs-content#3285