Add changesets support

Author: juanpprieto

.changeset/config.json

@@ -0,0 +1,19 @@
+{
+  "$schema": "https://unpkg.com/@changesets/config@2.2.0/schema.json",
+  "changelog": [
+    "",
+    {
+      "repo": "shopify/js-buy-sdk"
+    }
+  ],
+  "commit": false,
+  "fixed": [],
+  "linked": [],
+  "access": "public",
+  "baseBranch": "main",
+  "updateInternalDependencies": "patch",
+  "privatePackages": {
+    "version": true,
+    "tag": true
+  }
+}

.changeset/sixty-roses-learn.md

@@ -0,0 +1,5 @@
+---
+"shopify-buy": patch
+---
+
+Adding changeset and github ci release with provenance