Add usage examples for Asset Options (#283)

* Add usage examples for Asset Options

* Update src/api/options-assets.md

Co-authored-by: Natalia Tepluhina <tarya.se@gmail.com>

* Update src/api/options-assets.md

Co-authored-by: Natalia Tepluhina <tarya.se@gmail.com>

Co-authored-by: Natalia Tepluhina <tarya.se@gmail.com>

Author: CyberAP

src/api/options-assets.md

@@ -8,6 +8,22 @@
 
   A hash of directives to be made available to the component instance.
 
+- **Usage:**
+  ```js
+  const app = Vue.createApp({})
+  
+  app.component('focused-input', {
+    directives: {
+      focus: {
+        mounted(el) {
+          el.focus()
+        }
+      }
+    },
+    template: `<input v-focus>`
+  })
+  ```
+
 - **See also:** [Custom Directives](../guide/custom-directive.html)
 
 ## components
@@ -18,4 +34,18 @@
 
   A hash of components to be made available to the component instance.
 
+- **Usage:**
+  ```js
+  const Foo = {
+    template: `<div>Foo</div>`
+  }
+  
+  const app = Vue.createApp({
+    components: {
+      Foo
+    },
+    template: `<Foo />`
+  })
+  ```
+
 - **See also:** [Components](../guide/component-basics.html)