Upgrade to Next.js 16 with Turbopack and Contentlayer2

- Upgraded Next.js to v16, React to v19
- Migrated from contentlayer to contentlayer2
- Migrated to Turbopack by decoupling Contentlayer from webpack
- Updated all page components to handle async params (Next.js 15+ breaking change)
- Changed package.json to type: module and renamed config files to .cjs
- Updated README with current tech stack and article creation instructions
- Fixed tag encoding issue (removed double encoding)
- All security vulnerabilities resolved (npm audit: 0 vulnerabilities)

postcss.config.cjs

@@ -0,0 +1,6 @@
+module.exports = {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+};