fix(Docs): update effects description (#164)

Author: Mobiletainment

README.md

@@ -10,7 +10,7 @@ Reactive libraries for Angular
 ## Packages
 
 - [@ngrx/store](./docs/store/README.md) - RxJS powered state management for Angular applications, inspired by Redux  
-- [@ngrx/effects](./docs/effects/README.md) - Side Effect model for @ngrx/store to model UI events as an additional sources oF actions.   
+- [@ngrx/effects](./docs/effects/README.md) - Side Effect model for @ngrx/store to model event sources as actions.   
 - [@ngrx/router-store](./docs/router-store/README.md) - Bindings to connect the Angular Router to @ngrx/store  
 - [@ngrx/store-devtools](./docs/store-devtools/README.md) - Store instrumentation that enables a
 [powerful time-travelling debugger](https://chrome.google.com/webstore/detail/redux-devtools/lmhkpmbekcpmknklioeibfkpmmfibljd?hl=en).