add: TailwindFlex & Astro Cactus (#514)

Co-authored-by: Enzo Innocenzi <enzo@innocenzi.dev>

README.md

@@ -312,6 +312,7 @@
 - 🧩 [Pines UI](https://devdojo.com/pines) - Alpine and Tailwind CSS UI library.
 - 🧩 [NativeWind](https://www.nativewind.dev) - NativeWind uses Tailwind CSS as scripting language to create a universal style system for React Native.
 - 🧩 [Windstatic](https://windstatic.com) - Set of 161 elements & layouts made with Tailwind CSS and Alpine.js.
+- 🧩 [TailwindFlex](https://tailwindflex.com) - Free library of Tailwind CSS examples.
 - 📁 [Vue Notus](https://www.creative-tim.com/product/vue-notus) - Open-source Tailwind CSS and Vue.js UI kit.
 - 📁 [Red Pixel Themes](https://redpixelthemes.com/) - Paid, developer-friendly templates made with Tailwind CSS.
 - 📁 [EasyTailwind](https://easytailwind.now.sh) - Freemium, easily customizable templates made with Tailwind CSS.
@@ -331,6 +332,7 @@
 - 📁 [Admin One React](https://github.com/justboil/admin-one-react-tailwind) - Free React.js Tailwind CSS admin template with Next.js & TypeScript.
 - 📁 [Flowbite Admin Dashboard](https://github.com/themesberg/flowbite-admin-dashboard) - Open-source admin dashboard template built with Tailwind CSS and Flowbite.
 - 📁 [Astro Template Resume](https://github.com/fortezhuo/fortezhuo.my.id) - Eye-catching resume template built with Astro, Tailwind CSS.
+- 📁 [Astro Template Cactus](https://github.com/chrismwilliams/astro-theme-cactus) - Tailwind CSS Astro starter template.
 
 ## Starters & Themes