Clean atomic and axin theme

[BarbUk]

Description

• axin theme was just linted
• atomic theme needed an update of the args parsing in internal function to be compliant with shellcheck:

args=($1)

become

read -r -a args <<< "$@"

Motivation and Context

#1696

How Has This Been Tested?

Tested both theme by using before and after the update

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• If my change requires a change to the documentation, I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• If I have added a new file, I also added it to clean_files.txt and formatted it using lint_clean_files.sh.
• I have added tests to cover my changes, and all the new and existing tests pass.

[NoahGorny]

Seems to work great, thank you @BarbUk!
This just needs a rebase, otherwise LGTM

[NoahGorny]

Thanks @BarbUk! Well done 😄