FMEPRD-189 Update Datadog Integration Documentation

[alai97]

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Description

• Please describe your changes: Flagged by Dave K on Slack. Reflects the same changes that are live on the Zendesk article. Also took the opportunity to do a UI screenshot refresh as the Datadog application has changed since the first batch of screenshots were added 💜
• Jira/GitHub Issue numbers (if any): https://harness.atlassian.net/browse/FMEPRD-189
• Preview links/images (Internal contributors only): https://684b71c9a8dcba759ce46d20--harness-developer.netlify.app/docs/feature-management-experimentation/integrations/datadog

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[bot-gitexp-user]

Please check the Execution Link of the Pipeline for the Website Draft URL. This is located in the Preview Step behind the Harness VPN and also is available in #hdh_alerts. E.g Website Draft URL: https://unique-id--harness-developer.netlify.app. Current Draft URL is: https://684b6c5af506d3749c29b448--harness-developer.netlify.app

[bot-gitexp-user]

Please check the Execution Link of the Pipeline for the Website Draft URL. This is located in the Preview Step behind the Harness VPN and also is available in #hdh_alerts. E.g Website Draft URL: https://unique-id--harness-developer.netlify.app. Current Draft URL is: https://684b6ce05a8771737e84b7cc--harness-developer.netlify.app

[dtk-DaveKarow]

@alai97 Please don't remove "Datadog RUM" from the final heading:
"Using Split with Datadog RUM" should not become "Datadog Harness FME integration"

Why? Because there are two separate integrations... one takes split flag change events and sends them to Datadog, and the other lets Datadog's RUM product enrich data with flag evaluations on the client side.

[bot-gitexp-user]

Please check the Execution Link of the Pipeline for the Website Draft URL. This is located in the Preview Step behind the Harness VPN and also is available in #hdh_alerts. E.g Website Draft URL: https://unique-id--harness-developer.netlify.app. Current Draft URL is: https://684b71c9a8dcba759ce46d20--harness-developer.netlify.app