[Kibana][9.1 & Serverless] Update ML docs to reflect new nav

[nastasha-solomon]

Fixes #1891 by refreshing nav instructions. These changes are only added to 9.1 and Serverless, so there will be no corresponding 8.19 PR.

Previews

[github-actions]

🔍 Preview links for changed docs

• explore-analyze/machine-learning/anomaly-detection/geographic-anomalies.md
• explore-analyze/machine-learning/anomaly-detection/mapping-anomalies.md
• explore-analyze/machine-learning/anomaly-detection/ml-ad-run-jobs.md
• explore-analyze/machine-learning/anomaly-detection/ml-configuring-categories.md
• explore-analyze/machine-learning/anomaly-detection/ml-configuring-populations.md
• explore-analyze/machine-learning/anomaly-detection/ml-reverting-model-snapshot.md
• explore-analyze/machine-learning/data-frame-analytics/ml-dfa-classification.md
• explore-analyze/machine-learning/data-frame-analytics/ml-dfa-finding-outliers.md
• explore-analyze/machine-learning/data-frame-analytics/ml-dfa-regression.md
• explore-analyze/machine-learning/data-frame-analytics/ml-trained-models.md

More links …

• explore-analyze/machine-learning/nlp/ml-nlp-e5.md
• explore-analyze/machine-learning/nlp/ml-nlp-elser.md
• explore-analyze/machine-learning/nlp/ml-nlp-inference.md
• explore-analyze/machine-learning/setting-up-machine-learning.md

[mdbirnstiehl]

One minor thing, but otherwise LGTM!

[szabosteve]

LGTM, thanks!

[shainaraskas]

are these instructions appropriate for 9.0 users as well? we might have to provide a forked path so 9.0 users can still find their way.

[nastasha-solomon]

@shainaraskas good catch - from the Stack perspective, these changes are only being introduced in 9.1, so the "old" instructions are still relevant to users on 9.0.x.

RE creating a forked path:
I'm a bit hesitant to include both paths in the docs as they'd make for reaallly long and overwhelming instructions. Instead, I'm considering reducing the nav instruction down to "Find < This ML page > in the main menu or use the global search field." I know it's pretty bare bones, but it is the cleaner and more sustainable option in case the nav changes again.

[alvarezmelissa87]

LGTM ⚡