fix: add typings

Author: barelyhuman

.sizesnap.json

@@ -1,8 +1,8 @@
 {
   "dist/index.d.ts": {
-    "size": "79B",
-    "brotli": "57B",
-    "gzip": "82B"
+    "size": "157B",
+    "brotli": "98B",
+    "gzip": "133B"
   },
   "dist/index.js": {
     "size": "2.811KB",

src/index.js

@@ -12,6 +12,11 @@ const delimiterRegexGlobal = new RegExp(delimiterComment, 'g')
 
 const eventRegex = /(@)(\w+)=["']$/
 
+/**
+ *
+ * @param {import("@arrow-js/core").ArrowTemplate} template
+ * @return {string}
+ */
 export function renderToString(template) {
   const isT = 'isT' in template
   // FIXME: not a template, throw an error instead,