fix: Add nixpacks configuration for Astro deployment

dealplustech-astro/node_modules/astro/dist/env/config.js

@@ -0,0 +1,21 @@
+const envField = {
+  string: (options) => ({
+    ...options,
+    type: "string"
+  }),
+  number: (options) => ({
+    ...options,
+    type: "number"
+  }),
+  boolean: (options) => ({
+    ...options,
+    type: "boolean"
+  }),
+  enum: (options) => ({
+    ...options,
+    type: "enum"
+  })
+};
+export {
+  envField
+};