Remove custom templates snippet

[apinnick]

What changes are you introducing?

Removing guides/common/modules/snip_note-custom-templates-unsupported.adoc

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

Snippet is very short and used only once.

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

No tech review or testing required.

Contributor 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 3.16/Katello 4.18 (Satellite 6.18)
• Foreman 3.15/Katello 4.17
• Foreman 3.14/Katello 4.16 (Satellite 6.17; orcharhino 7.4)
• Foreman 3.13/Katello 4.15 (EL9 only)
• Foreman 3.12/Katello 4.14 (Satellite 6.16; orcharhino 7.2 on EL9 only; orcharhino 7.3)
• 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)
• We do not accept PRs for Foreman older than 3.9.

Review checklists

Tech review (performed by an Engineer who did not author the PR; can be skipped if tech review is unnecessary):

• The PR documents a recommended, user-friendly path.
• The PR removes steps that have been made unnecessary or obsolete.
• Any steps introduced or updated in the PR have been tested to confirm that they lead to the documented end result.

Style review (by a Technical Writer who did not author the PR):

• The PR conforms with the team's style guidelines.
• The PR introduces documentation that describes a user story rather than a product feature.

[github-actions]

The PR preview for 392b2bb is available at theforeman-foreman-documentation-preview-pr-4254.surge.sh

The following output files are affected by this PR:

• Managing_Hosts/index-foreman-deb.html
• Managing_Hosts/index-foreman-el.html
• Managing_Hosts/index-katello.html

show diff

show diff as HTML

[maximiliankolb]

style-wise LGTM. Tech-wise: it should probably only be visible for Satellite and orcharhino. It's currently also visible for Katello: https://docs.theforeman.org/nightly/Managing_Hosts/index-katello.html#Customizing_the_Registration_Templates_managing-hosts

[maximiliankolb]

Thanks Avital, LGTM.