[DOCS] Name/workflow change for threat match rules > indicator match rules

[jmikell821]

Issue: elastic/kibana#81334

Descriptive text "Use indicators from intelligence sources to detect matching events and alerts."

• Update tile title to "Indicator Match". Reasoning: we can address more use cases related to watch lists & block lists, by calling it Indicator Match rule type.
• Change "Threat Index Patterns" -> "Indicator Index Patterns"
• Change "Threat Index Query" -> "Indicator Index Query"
• Change "Threat Mapping" -> "Indicator Mapping"

There is also a UI flow change we want to propose. Effectively its a repositioning of existing selections to make it easier to use the feature:

1. User selects Index Patterns and Threat Index Patterns
2. Next, User selects Threat Mapping Field (dropdown list) and Threat Index Field (dropdown list).
3. Next, user can fill in Custom query bar and Threat Index query bar. This would be for advanced users who want to further filter the datasets being matched.

Reasoning: Most users will only want to specify Threat Mapping Field and Threat Index field as part of the rule definition. There could be advanced users who want to apply additional filters, but we want to avoid starting a user with an advanced rule workflow.

[jmikell821]

PR #336 merged.