Browser Monitoring Content

[alai97]

What does this PR do?

Adds the actual image and video content for Browser Monitoring (https://github.com/DataDog/browser-sdk/pull/1693).

Motivation

#rum-docs Slack

https://docs-staging.datadoghq.com/alai97/browser-monitoring-initialization-example-update/real_user_monitoring/browser/

Additional Notes

Remember to update the pull_config.yaml file before merging!

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Reviewer checklist

• [ ] Review the changed files.
• [ ] Review the URLs listed in the Preview section.
• [ ] Check images for PII
• [ ] Review any mentions of "Contact Datadog support" for internal support documentation.