message: fix capitalisation of 'NodeJS'
diff: # Rotate a Key
  -Indy-SDK Developer Walkthrough #2, NodEJS Edition
  +Indy-SDK Developer Walkthrough #2, NodeJS Edition
  [ [Python](../python/README.md) | [Java](../java/README.md) | [.NET](../../not-yet-written.md) | [Objective C](../../not-yet-written.md) | [Rust](../rust/README.md)]
  