Change the default shell from BASH to FISH

[TeamLinux01]

Prerequisites

• I have searched open and closed issues for duplicates.

Feature

Change the default shell from BASH to FISH. Although keep BASH installed, as it is needed for a lot of scripts.

https://fishshell.com/
https://en.wikipedia.org/wiki/Friendly_interactive_shell

I am requesting this change as I think it goes with https://elementary.io/docs/human-interface-guidelines#design-philosophy as it makes using a terminal easier/friendlier to both new users and professionals.