Merge pull request #3 from Abdullah-l/patch-1

Fix typo in README.md

README.md

@@ -9,7 +9,7 @@ This library supports both Phase 1 and Phase 2. Phase 2 support is still new so
 
 ## Rubygems
 ```sh
-gem install zatca-zdk
+gem install zatca-sdk
 ```
 
 ## Bundler