add shadcn/ui + docs

docs/shadcn-ui/README.md

@@ -0,0 +1,30 @@
+# shadcn/ui
+
+shadcn/ui is UI component library for React components. Shadcn/ui is modular in comparison to other component libraries. You only install the components you really need and not import anything. Further is the code stored directly in the project, instead coming from a dependencie.
+
+Website shadcn/ui: https://ui.shadcn.com/
+
+Next.js docs: https://ui.shadcn.com/docs/installation/next
+
+Install shadcn/ui
+```zsh
+npx shadcn@latest init
+```
+
+Install a UI component
+```zsh
+npx shadcn@latest add <COMPONENT-NAME>
+```
+
+Usage in code
+```tsx
+import { Button } from "@/components/ui/button"
+
+export default function Home() {
+  return (
+    <div>
+      <Button>Click me</Button>
+    </div>
+  )
+}
+```