docs: select/demo/combobox.md - English translation (#3010)

English translation of labels and comments

components/select/demo/combobox.md

@@ -41,13 +41,13 @@ const Test = React.createClass({
     this.setState({ options });
   },
   render() {
-    // filterOption 需要设置为 false，数据是动态设置的
+    // filterOption needs to be false，as the value is dynamically generated
     return (
       <Select combobox
         style={{ width: 200 }}
         onChange={this.handleChange}
         filterOption={false}
-        placeholder="请输入账户名"
+        placeholder="Enter the account name"
       >
         {this.state.options}
       </Select>