docs: bee constructor exception (#45)

Author: AuHau

docs/user-documentation/getting-started.md

@@ -41,6 +41,7 @@ yarn add @ethersphere/bee-js --save
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 After that you need to import the Bee class and create a bee instance connecting to your Bee node (here we assume it runs on localhost on default port).
+Be aware, if you will pass invalid URL the constructor will throw an exception!
 
 
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