feat: Add sea-dark theme

[ghost]

Description

Added new sea-dark theme.

Type of change

• Updated documentation (updated the readme, templates, or other repo files)

How Has This Been Tested?

• Tested locally with a valid username
• Tested locally with an invalid username
• Ran tests with composer test
• Added or updated test cases to test new features

Checklist:

• I have checked to make sure no other pull requests are open for this issue
• The code is properly formatted and is consistent with the existing code style
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Screenshots

[DenverCoder1]

I kind of feel the white part seems out of place and would maybe be better with a dark color such as a dark blue or black.

Maybe something like #00546F would look good for the stroke?

Again, up to you. Let me know what you think.

[ghost]

Okay.

[ghost]

Ready.

[ghost]

I don't know why, but after I updated the branch to DenverCoder1/github-readme-streak-stats:main, the Prettier task failed in both pull requests.

[DenverCoder1]

Thanks!