Add custom provisioning snippet for SLES

[maximiliankolb]

What changes are you introducing?

Add new example for custom provisioning snippets for SUSE family

Why are you introducing these changes? (Explanation, links to references, issues, etc.)

We only had examples for Debian and EL.

Anything else to add? (Considerations, potential downsides, alternative solutions you have explored, etc.)

I have tested the installation command in a container.

Checklists

• I am okay with my commits getting squashed when you merge this PR.
• I am familiar with the contributing guidelines.

Please cherry-pick my commits into:

• Foreman 3.14/Katello 4.16
• Foreman 3.13/Katello 4.15 (EL9 only)
• Foreman 3.12/Katello 4.14 (Satellite 6.16)
• Foreman 3.11/Katello 4.13 (orcharhino 6.11 on EL8 only; orcharhino 7.0 on EL8+EL9; orcharhino 7.1 with Leapp)
• Foreman 3.10/Katello 4.12
• Foreman 3.9/Katello 4.11 (Satellite 6.15; orcharhino 6.8/6.9/6.10)
• Foreman 3.8/Katello 4.10
• Foreman 3.7/Katello 4.9 (Satellite 6.14)
• We do not accept PRs for Foreman older than 3.7.

[github-actions]

The PR preview for ca2d4bb is available at theforeman-foreman-documentation-preview-pr-3802.surge.sh

The following output files are affected by this PR:

• Provisioning_Hosts/index-foreman-deb.html
• Provisioning_Hosts/index-foreman-el.html
• Provisioning_Hosts/index-katello.html
• Provisioning_Hosts/index-orcharhino.html
• Provisioning_Installer/index-foreman-deb.html
• Provisioning_Installer/index-foreman-el.html
• Provisioning_Installer/index-katello.html
• Provisioning_Installer/index-orcharhino.html

show diff

show diff as HTML

[Lennonka]

Style-wise LGTM.

However, I'm not sure if it adds any value for the user when it's almost the same as the example for EL. Not blocking it, though.