doc: add instruction to solve js dependency in README

Signed-off-by: Shengqi Chen <[email protected]>

README.md

@@ -23,6 +23,15 @@ Note that due to API limitations, not all operations are supported on all platfo
 
 This library uses [ndef](https://pub.dev/packages/ndef) for NDEF record encoding & decoding.
 
+## Dependency issue of `js` package
+
+Since v3.5.0, `flutter_nfc_kit` depends on `js: ^0.7.1`. This might lead to a conflict with other packages that depend on `js: ^0.6.4`. If you do not use this plugin in a web environment, you can safely add the following to your `pubspec.yaml` to resolve the conflict:
+
+```yaml
+dependency_overrides:
+  js: "^0.6.4"
+```
+
 ## Setup
 
 Thank [nfc_manager](https://pub.dev/packages/nfc_manager) plugin for these instructions.