Theme cycle feature added with dark | light | system modes

[ElshadHu]

Changes

Modified the theme toggle functionality to support three modes instead of two:

• Updated useTheme.tsx to include system theme detection using window.matchMedia('prefers-color-scheme: dark')
• Added dynamic listener to respond to OS/browser theme changes in real-time
• Modified Theme.tsx to display appropriate icons for each mode (moon, sun, half-circle)
• Incremented version in package.json from 2.2.1 to 2.3.0 according to semantic versioning

Why Needed

Users previously could only toggle between dark and light modes manually. This enhancement adds a system mode that automatically follows the user's OS/browser theme preference, providing a more seamless experience for users who have already configured their system-wide theme settings.

Closes #16

Testing

Verification can be made:

• Click the theme toggle to go through all three options
• In system mode, verify the website matches your OS/browser theme preference
• Change your OS theme to confirm automatic updates (can be done via browser DevTools theme emulation)

[ElshadHu]

Hi maintainers, thank you for reviewing this contribution. I'm participating in Hacktoberfest this October - would you consider adding the 'hacktoberfest' topic to this repository? Either way, I'm glad to contribute to the project.If there is an issue with PR, let me know.

[physicshub]

Hello, thank you for the pull request, I think it's completely fine and I'm going to merge it. As I've said to other contributors, the changes will be live as soon as I deploy the repo to gh pages, and I won't do so until the Google Translate system is fixed. I'll let you know when it's live. As for Hacktoberfest, I'll post the topic without any hesitation.

Thanks again for your invaluable help!

[physicshub]

@all-contributors please add @ElshadHu code

[allcontributors]

@physicshub

I've put up a pull request to add @ElshadHu! 🎉

[physicshub]

I added you to the README contributors section. I invite you also to join our discord to get in touch with other contributors and get a special role. https://discord.gg/qsA9KvrNKk

[ElshadHu]

Thank you so much for merging my PR and adding me to the contributors! I really appreciate it. I'll join the Discord server to connect with the team.

[physicshub]

Hello! Your changes are now live!

[ElshadHu]

Awesome, thank you! Glad to see it live.