Update Rootless Podman/RHEL docs

[EmilyRagan]

The Rootless Podman Guide needs to be reviewed and updated. For example, step 6 instructs the user to

Edit compose.yaml and uncomment the user: 0:0 lines and comment the user: "${OPENC3_USER_ID}:${OPENC3_GROUP_ID}" lines
but the user: 0:0 lines were removed in December 2023 and openc3.sh handles this now. The whole guide should be reviewed for accuracy.

[crawlchat]

Thanks for flagging this! You're right — the user: 0:0 lines were removed from compose.yaml back in December 2023, and openc3.sh now handles setting OPENC3_USER_ID/OPENC3_GROUP_ID automatically at runtime. That makes step 6 in the Rootless Podman Guide outdated/incorrect as currently written.

I don't have enough context here to confirm which other specific steps in the guide are stale (permissions setup, DOCKER_HOST config, logging driver notes, etc. have also come up as pain points in related issues). I've logged this as a documentation gap so the team can do a full review of the guide against current openc3.sh/compose.yaml behavior.

If you happen to know of other specific steps that are outdated (besides step 6), it'd help to list them here so the docs update can address everything in one pass.

[EmilyRagan]

• ulimit settings may need to be modified
• if provided for podman build, compose override file cannot be empty (or have everything commented out), but a simple services: {} is enough

[EmilyRagan]

I had to set the following on RHEL, but I imagine these settings could be unique per system

openc3-tsdb:
  ...
  ulimits:
    nofile:
      soft: 262144
      hard: 262144
    memlock:
      soft: 65536
      hard: 65536