Create appendix for list of zowe's datasets

[1000TurquoisePogs]

Resolves #3719

This ticket collects information about zowe datasets and puts it in one appendix so that it can be referenced in a way that does not conflict with the user's chosen install type.

Before this PR, information about certain datasets was included (incompletely) in both SMPE and convenience build install pages.
While the tables were useful, referencing them from elsewhere could result in an issue where someone might be brought to a convenience build reference when using SMPE instead, or vice versa.

Putting the information into an appendix allows it to be referenced in a neutral way to both install types.

It also will be useful in the future for handling documentation about upgrades and downgrades as in zowe/community#2305

This is a draft open to all feedback.
This would apply to both V2 and V3, but I havent made such updates without first gathering feedback.

[github-actions]

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[1000TurquoisePogs]

Also:

Our code and doc call some datasets "custom datasets" and i find this bizarre terminology.
Maybe it's just me. I'd prefer saying they're "instance datasets", but wont make that change now unless there's consensus.

[github-actions]

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