Add applies_to metadata

[theletterf]

Adds applies_to metadata for cumulative docs. See https://docs-v3-preview.elastic.dev/elastic/docs-builder/tree/main/syntax/applies

Contributes to https://github.com/elastic/docs-content-internal/issues/253

[github-actions]

🤖 GitHub comments

Expand to view the GitHub comments

Just comment with:

• run docs-build : Re-trigger the docs validation. (use unformatted text in the comment!)

[github-actions]

🔍 Preview links for changed docs

• docs/reference/advanced-topics.md
• docs/reference/aiohttp-server-support.md
• docs/reference/api-reference.md
• docs/reference/asgi-middleware.md
• docs/reference/azure-functions-support.md
• docs/reference/configuration.md
• docs/reference/django-support.md
• docs/reference/flask-support.md
• docs/reference/how-agent-works.md
• docs/reference/index.md

More links …

• docs/reference/instrumenting-custom-code.md
• docs/reference/lambda-support.md
• docs/reference/logs.md
• docs/reference/metrics.md
• docs/reference/opentelemetry-api-bridge.md
• docs/reference/performance-tuning.md
• docs/reference/run-tests-locally.md
• docs/reference/sanic-support.md
• docs/reference/sanitizing-data.md
• docs/reference/set-up-apm-python-agent.md
• docs/reference/starlette-support.md
• docs/reference/supported-technologies.md
• docs/reference/tornado-support.md
• docs/reference/upgrading-4-x.md
• docs/reference/upgrading-5-x.md
• docs/reference/upgrading-6-x.md
• docs/reference/upgrading.md
• docs/reference/wrapper-support.md
• docs/release-notes/breaking-changes.md
• docs/release-notes/deprecations.md
• docs/release-notes/index.md
• docs/release-notes/known-issues.md

[xrmx]

LGTM

[colleenmcginnis]

Minor suggestions below.