Move babel config to separate file

Jest struggles to read all babel configurations if directly inside package.json.

This now allows us to install nanoid 5 and pass all tests with it.

babel.config.json

@@ -0,0 +1,10 @@
+{
+  "presets": [
+    "@babel/preset-env",
+    "@babel/preset-react"
+  ],
+  "plugins": [
+    "@babel/plugin-transform-runtime",
+    "babel-plugin-transform-import-meta"
+  ]
+}