Add more guidance about configuring the internal queue

[dedemorton]

Need to add more guidance about when and why to configure the file spool and memory queue.

The content differs across Beats, so we will need to use some conditional coding to render content appropriately.

See #6902 (comment)

[botelastic]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[botelastic]

This issue doesn't have a Team:<team> label.

[zez3]

@dedemorton Now would be a good time, Thank you.