Move note in Ubuntu installation procedure (after Step 9)

[travisamartin]

Move note in Ubuntu installation procedure (after Step 9)

https://docs.nginx.com/nginx/admin-guide/installing-nginx/installing-nginx-plus/#install_debian_ubuntu

Description

A customer reported confusion with the placement of the “Learn how to pin NGINX Plus to a specific version” note in the Ubuntu installation procedure.
The note currently appears too early (above Step 9) and references updating the repository before users have actually downloaded the nginx-plus apt configuration.

This caused the customer to miss the correct sequencing and require support.

Current behavior

• The note appears before Step 9, which leads readers to run apt update too early.
• Users who want to pin a version may follow the wrong order and run into package errors.

Expected behavior

• The note should appear immediately after Step 9 (the wget step) so that users see it once they’ve downloaded the apt configuration.
• This ensures the repository is in place before attempting to update and pin versions.

Impact

• Reduces customer confusion when pinning NGINX Plus versions.
• Prevents unnecessary support cases caused by sequencing issues.

Suggested change

• Move the “Learn how to pin NGINX Plus to a specific version” note to appear directly after Step 9.
• Remove the redundant apt update inside the note since Step 10 already covers it, or clarify sequencing if needed.

Customer feedback