docs: Update MCW package README Destructuring Format (#4551)

Updated the MCW package README destructuring format by removing spaces around symbol and brace as per the readme-standards.md

Fixes #4550

(cherry picked from commit 797ebc8)

packages/material-components-web/README.md

@@ -23,7 +23,7 @@ npm install material-components-web
 import * as mdc from 'material-components-web';
 const checkbox = new mdc.checkbox.MDCCheckbox(document.querySelector('.mdc-checkbox'));
 // OR
-import { checkbox } from 'material-components-web';
+import {checkbox} from 'material-components-web';
 const checkbox = new checkbox.MDCCheckbox(document.querySelector('.mdc-checkbox'));
 ```