Added New Year's Theme to themes.json and created required files

[naeimehnajafi]

• Added the New Year's theme configuration to themes.json.
• Created newyear.html, newyear.css, and newyear.js files under the appropriate directory.
• Verified file paths and updated JSON configuration.

[mads256h]

We already have a new years theme. See the "fireworks" theme.

[JakobTopholt]

@mads256h I think she knows, the issue related to this PR asks for a huge rocket on the moment of midnight.

[mads256h]

@JakobTopholt I am just confused as to why a new theme is added

[krestenlaust]

@JakobTopholt I am just confused as to why a new theme is added

With the new theme system, themes can easily overlap, so you could just overlap the news rocket theme with the existing theme.

But with that said, it's a little silly to not build on top of the existing new year's rocket code

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.88%. Comparing base (a02bfdb) to head (62503e1).
Report is 8 commits behind head on next.

Additional details and impacted files

@@            Coverage Diff             @@
##             next     #547      +/-   ##
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+ Coverage   80.80%   80.88%   +0.07%     
==========================================
  Files          40       40              
  Lines        3809     3876      +67     
  Branches      481      487       +6     
==========================================
+ Hits         3078     3135      +57     
- Misses        675      684       +9     
- Partials       56       57       +1     

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[naeimehnajafi]

Hi,

I have integrated the rocket effect into the existing "fireworks" theme as per your guidance. The updates include:

• Adjustments in fireworks.css to incorporate the rocket visuals and animations.
• Updated fireworks.html to include the rocket’s <div> and logic.
• Verified and adjusted paths in themes.md and themes.json for consistency.
  Let me know any issues.
  Thank you for your help and patience!