feat: update "Deploy Slurm" howto to use new node names and set-node-state

[NucciTheBoss]

Pre-submission checklist

• I read and followed the CONTRIBUTING guidelines.
• I have ensured that the documentation tests complete successfully.

Summary of Changes

This PR updates the "Deploy Slurm" how-to use the new set-node-state action, and use the charm unit name as the node name rather than the machine hostname.

Other changes I made include:

1. Update the "Deploy Slurm" Terraform configuration files to use v1 of the Juju Terraform provider.
2. Shortened the deployment instructions to be more to the point. The tutorial is where we should elaborate more on things like the importance of integrations a models.
3. Created reusable assets for Terraform plans and admonitions that appear in multiple tabs.

Related Issues, PRs, and Discussions

• Closes Update node name references to charm unit names #111
• PR feat: update terraform module to juju terraform provider v1 filesystem-charms#27 is required to make the filesystem charm modules compatible with v1 of the Juju Terraform provider.

[AshleyCliff]

Nice work updating the language! I've tried to keep comments and suggestions on topic, there will likely be some structural updates to this page following this one.

[NucciTheBoss]

@AshleyCliff I've implemented your review feedback into this PR. The only thing I didn't address was your comment about providing the justification for why we need to use the constraint virt-type=virtual-machine when deploying Slurm on LXD. I think it's better if we create a dedicated Explanation doc that explains why we recommend against deploying the Slurm charms on system containers.

[AshleyCliff]

Looking good! Two quick tweak suggestions and then we're good to go.

[NucciTheBoss]

@AshleyCliff this PR should be good to go now! 👍

[AshleyCliff]

LGTM!