Feat: Support CLI completions in Docker containers

[brendanfalk]

Checks

• I could not find an existing setting that solved my issue
• I searched the discussions in this repo and there are no duplicates of my feature request

Feature Details

A lot of users run Docker containers locally and run an interactive shell to interact with them. We should support fast CLI completions on these machines.

If you have a specific machine you want support for, please comment!

[alanhe421]

I'm thinking that you still need to load the profile file in the container if you want to support it, otherwise you can't determine the PS1 and command contents.

[brendanfalk]

Agree!