README.md in stellar-sdk-0.5.0 vs README.md in stellar-sdk-0.6.0

@@ -43,9 +43,15 @@
   to:     recipient,
   amount: Stellar::Amount.new(100_000_000)
 }) 
 ```
 
+Be sure to set the network when submitting to the public network (more information in [stellar-base](https://www.github.com/stellar/ruby-stellar-base)):
+
+```ruby
+Stellar.default_network = Stellar::Networks::PUBLIC
+```
+
 ## Development
 
 - Copy `spec/config.yml.sample` to `spec/config.yml`
 - Replace anything in `spec/config.yml` especially if you will re-record specs
 - `rspec spec`