add landing and subscription plans

Signed-off-by: Omar Sánchez Pizarro <omar.sanchez@pistacero.net>

web/landing/astro.config.mjs

@@ -0,0 +1,9 @@
+import { defineConfig } from 'astro/config';
+import tailwind from '@astrojs/tailwind';
+
+// https://astro.build/config
+export default defineConfig({
+  integrations: [tailwind()],
+  output: 'static',
+});
+