Use HTTPS repository metadata

[snkk2x-collab]

Summary

• Change the package repository metadata from an SSH URL to the equivalent HTTPS GitHub URL.
• This makes the npm package metadata easier to follow in environments without SSH credentials.

Validation

• node package metadata assertion
• git diff --check
• git ls-remote https://github.com/ttskch/prettier-plugin-tailwindcss-anywhere.git HEAD
• pnpm install --frozen-lockfile
• pnpm biome ci
• pnpm test
• pnpm build
• pnpm test:coverage
• pnpm pack --dry-run

Note: local validation used Node v24.14.0, while current main declares >= 20.9 < 24, so pnpm emitted engine warnings. The commands above still completed successfully.