docs: update the interface blueprint docs

Author: Brocco

docs/documentation/generate/interface.md

@@ -6,6 +6,19 @@
 `ng generate interface [name] <type>` generates an interface
 
 ## Options
-`--app` Specifies app name or index to use.
+<details>
+  <summary>app</summary>
+  <p>
+    `--app` (alias: `-a`) _default value: 1st app_
+  </p>
+  <p>
+    Specifies app name to use.
+  </p>
+</details>
 
-`type` Optional String to specify the type of interface.
+<details>
+  <summary>type</summary>
+  <p>
+    Optional String to specify the type of interface.
+  </p>
+</details>