[Request] Add table that maps Beats modules to Fleet integrations

## Description

This was opened against the Fleet / integration documentation for version 8.2.

There is documentation for migrating from Beats to Elastic Agent (https://github.com/elastic/observability-docs/issues/745) however, it does not provide any assistance for mapping the existing Beats modules and inputs to their Fleet integration equivalent. It would be helpful if the ["Prepare for migration"](https://www.elastic.co/guide/en/fleet/8.2/migrate-beats-to-agent.html#prepare-for-migration) section included or linked to the decoder or mapping of the "old" Beat functionality to "new" integration functionality.

For example, something like this on a sub-page of the migration directions

| Beat | Module | type | Fleet integration | Type | Sub-type|
|------|----------|-------|-------------------|--------|---------|
| [Filebeat](https://www.elastic.co/guide/en/beats/filebeat/current/index.html) | [inputs](https://www.elastic.co/guide/en/beats/filebeat/current/configuration-filebeat-options.html) | [log](https://www.elastic.co/guide/en/beats/filebeat/current/filebeat-input-log.html) | [Custom Logs](https://docs.elastic.co/integrations/log) | |
| [Filebeat](https://www.elastic.co/guide/en/beats/filebeat/current/index.html) | [System](https://www.elastic.co/guide/en/beats/filebeat/current/filebeat-module-system.html) | system | [System](https://docs.elastic.co/en/integrations/system) | [logs](https://docs.elastic.co/en/integrations/system#logs) | [system](https://docs.elastic.co/en/integrations/system#system) |
| [Filebeat](https://www.elastic.co/guide/en/beats/filebeat/current/index.html) | [System](https://www.elastic.co/guide/en/beats/filebeat/current/filebeat-module-system.html) | auth | [System](https://docs.elastic.co/en/integrations/system) | [logs](https://docs.elastic.co/en/integrations/system#logs) | [auth](https://docs.elastic.co/en/integrations/system#auth) |
| [Filebeat](https://www.elastic.co/guide/en/beats/filebeat/current/index.html) | [Auditd](https://www.elastic.co/guide/en/beats/filebeat/current/filebeat-module-auditd.html) | log | [Auditd logs](https://docs.elastic.co/integrations/auditd) | [logs](https://docs.elastic.co/integrations/auditd#auditd-logs) | [logs](https://docs.elastic.co/integrations/auditd#auditd-logs) |

Our users can get confused trying to trying to do the mapping as it is not as clear, for example "Auditbeat". Some of the individual module pages, for example [Filebeat's system module](https://www.elastic.co/guide/en/beats/filebeat/8.2/filebeat-module-system.html), may link to the integration but these are time consuming to go through for a many data source on multiple types of Beats deployment.

We should make this decoding table to make the transition from Beats to Elastic Agent quicker, easier, less confusing, and less uncertain.

## Collaboration
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- The docs team will lead producing the content
- The product team will provide the initial content and the docs team will edit / review
- The docs team will define with product team the structure and location, and the product team will provide the initial content
- Other (please describe)

*(Assign a contact person for this issue. We need to have a contact person in the product/development team to provide information about how the item to be documented works. This can be omitted when the product/development team is providing the initial content, as the contact person will be the one making the initial contribution.)*

**Contact Person:**

## Suggested Target Release

*(Let us know if this feature is needed for a specific release.)*

## Stakeholders

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