Change readme to reflect new ember-cli addon syntax
Change readme to reflect new ember-cli addon syntax

ember-cli has changed the addon install command from `ember install:addon <addon name>` to `ember install <addon name>`.  This just changes the readme to show that.
igorrKurr/ember-localforage-adapter,sebweaver/ember-localforage-adapter,Flexberry/ember-localforage-adapter,sebweaver/ember-localforage-adapter,igorrKurr/ember-localforage-adapter,tchak/ember-offline-adapter,Flexberry/ember-localforage-adapter,tchak/ember-offline-adapter