[Docs] podman-systemd.unit man page errors

Issue Description

Reading through the new podman-systemd documentation for version 4.4.0 (as of a5ca732), I noticed a few of errors (and potential errors):

In the "Valid options for [Container]" table:

• Label="YXZ" maps to --label "XYZ" – typo in the former.
• RemapGid=keep-id maps to --group-add keep-id – not sure if this is an error, but keep-id is not mentioned in the --group-add description in the podman run docs (neither for the latest nor v4.4 tags)—the special flag keep-groups is, though.
  • keep-id is mentioned again in the expanded RemapGid description under the table.
  • The "Valid options for [Kube]" table has this, too, but the docs for podman kube play don't include a --group-add option at all (and I didn't see a mention of extra options being passed through to a different command, which might be happening..?)

In the RemapUsers= section beneath the [Container] table, the last sentence cuts off: "Use RemapUid and"

In addition, there doesn't seem to be a link to https://docs.podman.io/en/latest/markdown/podman-systemd.unit.5.html anywhere within the docs.podman.io site that I can see. It can be found with the search function, but I initially didn't know to look for it when looking for info about Quadlet integration in Podman 4.4.0. It's the only man(5) page, so not a good fit for the Commands page where everything is man(1), but only being accessible via the Search function isn't great either.

Steps to reproduce the issue

Steps to reproduce the issue

1. Read https://github.com/containers/podman/blob/main/docs/source/markdown/podman-systemd.unit.5.md
2. Notice errors
3. ???
4. Profit!

Describe the results you received

N/A

Describe the results you expected

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podman info output

N/A

Podman in a container

No

Privileged Or Rootless

None

Upstream Latest Release

Yes

Additional environment details

N/A

Additional information

No response