CB-5908: add notice about file usage
CB-5908: add notice about file usage

Make it clear to developers that these files do not automatically flow into
a new project created with the CLI. This should get corrected when support
for icons and splashscreens is added to the CLI.

agilemation/cordova-app-hello-world,apache/cordova-app-hello-world,stgnet/cordova-app-hello-world,jsoref/cordova-app-hello-world,apache/cordova-app-hello-world,hypery2k/cordova-demo-app,hypery2k/cordova-demo-app,hypery2k/cordova-demo-app,jensaug/cordova-app-hello-world,hypery2k/cordova-demo-app,jsoref/cordova-app-hello-world,jensaug/cordova-app-hello-world,agilemation/cordova-app-hello-world,stgnet/cordova-app-hello-world