Release v0.4.0

What's Changed

• chore: bump version to 0.4.0 [skip ci] (12f5881)
• Merge branch 'main' of https://github.com/EXOTU/EXOTU_website (af33459)
• feat: add SEO optimization, Open Graph image, and site URL configuration (77f8abe)

Full Changelog: 6e3d434...af33459