select user in install scripts

[ChopinF]

Changes

• I resolved the Todo regarding the user selection instead of continuing with the current user as previously
• I have tested the changes locally
• I have removed check list and any unused sections
• I chose the next branch instead of main for the pr

[github-actions]

Hi @ChopinF! 👋

It appears to us that you are adding a new feature to Coolify.
We kindly ask you to also update the Coolify Documentation to include information about this new feature.
This will help ensure that our documentation remains accurate and up-to-date for all users.

Coolify Docs Repository: https://github.com/coollabsio/coolify-docs
How to Contribute to the Docs: https://coolify.io/docs/get-started/contribute/documentation

[ChopinF]

Hello @Cinzya , should I add in coolify-docs / docs / get-started / installation.md -> my part with user selection ?