message: better build process explanation
diff: @@ -34,7 +34,7 @@ We are using [SideeX](http://sideex.org/) as a start point. The SideeX team was
  ```peru sync```
  ```yarn``` or if using Node 10 ```yarn --ignore-engines```
  - Build the extension
  -```yarn build:ext``` or ```yarn build:ext:prod``` for production build
  +```yarn build:ext:prod``` or ```yarn build:ext``` for faster development build (also includes beta features)
  - Install as developer on [Google Chrome](https://developer.chrome.com/extensions/getstarted#unpacked) or [Firefox](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Temporary_Installation_in_Firefox)
  Manifest located in `<Project Directory>/packages/selenium-ide/build/manifest.json`
  