README.md in shodanz-1.0.4 vs README.md in shodanz-1.0.5

- old
+ new

@@ -9,11 +9,12 @@
 ## Usage
 
 ```ruby
 require "shodanz"
 
-client = Shodanz.client.new
+client = Shodanz.client.new(key: "YOUR_API_KEY")
 ```
+> You can also set the `SHODAN_API_KEY` environment variable instead of passing the API key as an argument when creating a client.
 
 ## REST API
 
 The REST API provides methods to search Shodan, look up hosts, get summary information on queries and a variety of utility methods to make developing easier. Refer to the [REST API](https://developer.shodan.io/api) documentation for more ideas on how to use it.
 