build: add postinstall 'svelte-kit sync' to ensure SvelteKit tsconfig is generated on Vercel

Author: gitcoder89431

package.json

@@ -7,6 +7,7 @@
 		"dev": "vite dev",
 		"build": "vite build",
 		"preview": "vite preview",
+		"postinstall": "svelte-kit sync",
 		"check": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json",
 		"check:watch": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json --watch",
 		"lint": "prettier --check . && eslint . --ext .js,.svelte",