docs(js): Add elementTimingIntegration documentation

[logaretm]

DESCRIBE YOUR PR

Document the new standalone elementTimingIntegration that collects Element Timing API data as Sentry distribution metrics. This replaces the deprecated enableElementTiming option on browserTracingIntegration.

Refs getsentry/sentry-javascript#19869

Changes:

• New integration doc page at docs/platforms/javascript/common/configuration/integrations/elementtiming.mdx
• Added elementTimingIntegration to the browser integrations table
• Added an "Integrations" section to the metrics page linking to the new integration

Note: The upstream SDK PR (getsentry/sentry-javascript#19869) has been merged but not yet released. This PR should be merged once the feature ships in a JS SDK release (expected 10.47.0). The SDK version in the alert will need to be updated to match the actual release version.

IS YOUR CHANGE URGENT?

Help us prioritize incoming PRs by letting us know when the change needs to go live.

• Urgent deadline (GA date, etc.):
• Other deadline:
• None: Not urgent, can wait up to 1 week+

SLA

• Teamwork makes the dream work, so please add a reviewer to your PRs.
• Please give the docs team up to 1 week to review your PR unless you've added an urgent due date to it.
  Thanks in advance for your help!

PRE-MERGE CHECKLIST

Make sure you've checked the following before merging your changes:

• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
sentry-docs	Ready	Preview, Comment	Mar 27, 2026 8:43pm

1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
develop-docs	Ignored		Mar 27, 2026 8:43pm