Document exclusion of JS libraries at build time
Document exclusion of JS libraries at build time

Also removes outdated information RE: serving JavaScript

Closes #57

tildeio/ember-cli-fastboot,ember-fastboot/ember-cli-fastboot,tildeio/ember-cli-fastboot,rwjblue/ember-cli-fastboot,kratiahuja/ember-cli-fastboot,josemarluedke/ember-cli-fastboot,josemarluedke/ember-cli-fastboot,rwjblue/ember-cli-fastboot,ember-fastboot/ember-cli-fastboot,kratiahuja/ember-cli-fastboot