Update README.md

Author: Dennis Charles Hackethal

packaging-distributing-electron-apps/README.md

@@ -7,4 +7,4 @@ Install [io.js](https://iojs.org/en/index.html).
 Within this folder run the terminal command `npm install` to install the
 `dependencies` and `devDependencies`.
 
-Then run `npm start` to run the app and `npm run builw` to build the distributable.
+Then run `npm start` to run the app and `npm run build` to build the distributable.