[Doc] rename component README file (#3662)

src/submit-bar/README.md

@@ -0,0 +1,99 @@
+# SubmitBar
+
+### Install
+
+``` javascript
+import { SubmitBar } from 'vant';
+
+Vue.use(SubmitBar);
+```
+
+## Usage
+
+### Basic Usage
+
+```html
+<van-submit-bar
+  :price="3050"
+  button-text="Submit"
+  @submit="onSubmit"
+/>
+```
+
+### Disabled
+
+`submit` event will not triggerd when disabled.
+
+```html
+<van-submit-bar
+  disabled
+  :price="3050"
+  button-text="Submit"
+  tip="Some tips"
+  tip-icon="info-o"
+  @submit="onSubmit"
+/>
+```
+
+### Loading
+
+`submit` event will not triggerd when loading.
+
+```html
+<van-submit-bar
+  loading
+  :price="3050"
+  button-text="Submit"
+  @submit="onSubmit"
+/>
+```
+
+### Advanced Usage
+
+Use slot to add custom contents.
+
+```html
+<van-submit-bar
+  :price="3050"
+  button-text="Submit"
+  @submit="onSubmit"
+>
+  <van-checkbox v-model="checked">Check</van-checkbox>
+  <span slot="tip">
+    Some tips, <span @click="onClickEditAddress">Link</span>
+  </span>
+</van-submit-bar>
+```
+
+## API
+
+### Props
+
+| Attribute | Description | Type | Default |
+|------|------|------|------|
+| price | Price |  `Number` | - |
+| label | Price left label |  `String` | `Total：` |
+| suffix-label | Price right label | `String` | - |
+| button-text | Button text | `String` | - |
+| button-type | Button type |  `String` | `danger` |
+| tip | Tip |  `String` | - |
+| tip-icon | Icon |  `String` | - |
+| disabled | Whether to disable button |  `Boolean` | `false` |
+| loading | Whether to show loading icon |  `Boolean` | `false` |
+| currency | Currency symbol |  `String` | `¥` |
+| decimal-length | Number of digits to appear after the decimal point | `Number` | `2` |
+| safe-area-inset-bottom | Whether to enable bottom safe area adaptation, to enable those features use `viewport-fit=cover` in the `viewport` meta tag | `Boolean` | `false` |
+
+### Events
+
+| Event | Description | Arguments |
+|------|------|------|
+| submit | Triggerd when click submit button | - |
+
+### Slots
+
+| Name | Description |
+|------|------|
+| default | Custom left content |
+| top | Custom top content |
+| tip | Custom tips |