Change recommended template priority in documentation

[skh]

We (the Fleet team) have found a potential conflict between the index template priority that is suggested on https://www.elastic.co/guide/en/elasticsearch/reference/current/index-templates.html , and the one the Fleet project uses for autogenerated index templates. Both use a priority of 200.

This issue is a request to recommend a higher priority than 200 in the documentation so users don't risk conflicts with Fleet-generated index templates should they wish to use Fleet at a later point.

The original discussion is in elastic/kibana#90299

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The original issue description is:

Currently, we use the following priorities for built-in or generated index templates:

• 100 for the built-ins metrics-*-*, logs-*-*, and synthetics-*-*, those come from elasticsearch, see https://www.elastic.co/guide/en/elasticsearch/reference/current/index-templates.html
• 200 for generated index templates for data streams of integrations (see [EPM] Conditionally generate ES index pattern name based on dataset_is_prefix kibana#89870)
• 150 for generated index templates for data streams of integrations when dataset_is_prefix is true (also see [EPM] Conditionally generate ES index pattern name based on dataset_is_prefix kibana#89870)

The priority 200 might conflict with what we suggest people do in the elasticsearch documentation linked above:

For example, if you don’t use the Elastic Agent and want to create a template for the logs-* index pattern, assign your template a priority of 200. This ensures your template is applied instead of the built-in template for logs--.

[elasticmachine]

Pinging @elastic/es-docs (Team:Docs)

[elasticmachine]

Pinging @elastic/es-core-features (Team:Core/Features)