fix(ts-bindings): package.json needs type: module

Since we started using `module: nodenext` in tsconfig.json, we need to
tell libraries that import these ones that the exported code is an ES
Module.

This fixes github.com/stellar/soroban-astro-template to work with
libraries generated with `soroban contract bindings typescript`

cmd/crates/soroban-spec-typescript/src/project_template/package.json

@@ -1,17 +1,18 @@
 {
   "version": "0.0.0",
   "name": "INSERT_CONTRACT_NAME_HERE",
+  "type": "module",
+  "exports": "./dist/index.js",
+  "typings": "dist/index.d.ts",
+  "scripts": {
+    "build": "tsc"
+  },
   "dependencies": {
     "@stellar/freighter-api": "2.0.0",
     "buffer": "6.0.3",
     "@stellar/stellar-sdk": "12.0.0-rc.3"
   },
-  "scripts": {
-    "build": "tsc"
-  },
-  "exports": "./dist/index.js",
-  "typings": "dist/index.d.ts",
   "devDependencies": {
     "typescript": "5.3.3"
   }
-}
+}