update docs

Author: hunterliu1003

README.md

@@ -39,7 +39,7 @@ features:
 
 ## Install
 
-### Vue 3.0
+**Vue 3.0**
 
 NPM:
 
@@ -53,7 +53,7 @@ Yarn:
 yarn add vue-final-modal@next
 ```
 
-### Vue 2.x
+**Vue 2.x**
 
 NPM:
 
@@ -69,7 +69,7 @@ yarn add vue-final-modal
 
 ## Basic usage
 
-1. Import and register the modal component.
+**1. Import and register the modal component.**
 
 ```js
 import { VueFinalModal } from 'vue-final-modal'
@@ -81,21 +81,21 @@ export default {
 }
 ```
 
-2. Add the modal component to the template.
+**2. Add the modal component to the template.**
 
 ```html
 <vue-final-modal v-model="showModal">
   Modal Content Here
 </vue-final-modal>
 ```
 
-3. Create a button to toggle the modal.
+**3. Create a button to toggle the modal.**
 
 ```html
 <button @click="showModal = true">Launch</button>
 ```
 
-4. All default props
+**4. All default props**
 
 ```js
 const CLASS_TYPES = [String, Object, Array]
@@ -118,7 +118,7 @@ const CLASS_TYPES = [String, Object, Array]
 }
 ```
 
-5. Events.
+**5. Events.**
 
 - @before-open: Before open
 - @opened: When opened