docs(generators:app): create app.md

[skip ci]

Author: Awk34

docs/generators/app.md

@@ -0,0 +1,17 @@
+### App
+Sets up a new AngularJS + Express app, generating all the boilerplate you need to get started.
+
+Usage:
+```bash
+Usage:
+  yo angular-fullstack:app [options] [<name>]
+
+Options:
+  -h,   --help          # Print the generator's options and usage
+        --skip-cache    # Do not remember prompt answers                        Default: false
+        --skip-install  # Do not install dependencies                           Default: false
+        --app-suffix    # Allow a custom suffix to be added to the module name  Default: App
+
+Arguments:
+  name    Type: String  Required: false
+```