docs: update menu/select styles and add snackbar to main readme (#927)

Author: Matt Goo

README.md

@@ -34,6 +34,7 @@ Component | Spec | MDC Web
 [Radio](./packages/radio) | [Radio Design Page](https://material.io/design/components/selection-controls.html#radio-buttons) | [MDC Radio](https://github.com/material-components/material-components-web/tree/master/packages/mdc-radio)
 [Ripple](./packages/ripple) | [Ripple Design Page](https://material.io/design/interaction/states.html) | [MDC Ripple](https://github.com/material-components/material-components-web/tree/master/packages/mdc-ripple)
 [Select](./packages/select) | [Select Design Page](https://material.io/design/components/menus.html#) | [MDC Select](https://github.com/material-components/material-components-web/tree/master/packages/mdc-select)
+[Snackbar](./packages/snackbar) | [Snackbar Design Page](https://material.io/design/components/snackbars.html) | [MDC Snackbar](https://github.com/material-components/material-components-web/tree/master/packages/mdc-snackbar)
 [Switch](./packages/switch) | [Switch Design Page](https://material.io/design/components/selection-controls.html#switches) | [MDC Switch](https://github.com/material-components/material-components-web/tree/master/packages/mdc-switch)
 [Tab](./packages/tab) | [Tabs Design Page](https://material.io/design/components/tabs.html) | [MDC Tab](https://github.com/material-components/material-components-web/tree/master/packages/mdc-tab)
 [Tab Bar](./packages/tab-bar) | [Tabs Design Page](https://material.io/design/components/tabs.html) | [MDC Tab Bar](https://github.com/material-components/material-components-web/tree/master/packages/mdc-tab-bar)

package.json

@@ -40,6 +40,7 @@
           "linear-progress",
           "list",
           "menu-surface",
+          "menu",
           "notched-outline",
           "radio",
           "ripple",

packages/menu/README.md

@@ -14,11 +14,15 @@ npm install @material/react-menu
 
 with Sass:
 ```js
+import '@material/react-list/index.scss';
+import '@material/react-menu-surface/index.scss';
 import '@material/react-menu/index.scss';
 ```
 
 with CSS:
 ```js
+import '@material/react-list/dist/menu.css';
+import '@material/react-menu-surface/dist/menu.css';
 import '@material/react-menu/dist/menu.css';
 ```
 

packages/select/README.md

@@ -14,11 +14,17 @@ npm install @material/react-select
 
 with Sass:
 ```js
+import '@material/react-list/index.scss';
+import '@material/react-menu-surface/index.scss';
+import '@material/react-menu/index.scss';
 import '@material/react-select/index.scss';
 ```
 
 with CSS:
 ```js
+import '@material/react-list/dist/menu.css';
+import '@material/react-menu-surface/dist/menu.css';
+import '@material/react-menu/dist/menu.css';
 import '@material/react-select/dist/select.css';
 ```
 
@@ -62,7 +68,7 @@ class MyApp extends React.Component {
   state = {value: 'pomsky'};
 
   onEnhancedChange = (index, item) => (
-    this.setState({value: item.getAttribute('data-value')});
+    this.setState({value: item.getAttribute('data-value')})
   );
 
   render() {