More shaving on design system

Summary: Added standardized dimensions for padding and gap, to encourage people to build layouts that look consistent, using for example `padv="small"`

Reviewed By: cekkaewnumchai

Differential Revision: D23961386

fbshipit-source-id: 33cd3b8974858e021a8b7d1b32f018fe3f007c63

desktop/app/src/MenuBar.tsx

@@ -27,6 +27,7 @@ import {notNull} from './utils/typeUtils';
 import constants from './fb-stubs/constants';
 import {Logger} from './fb-interfaces/Logger';
 import {NormalizedMenuEntry, buildInMenuEntries} from 'flipper-plugin';
+import {StyleGuide} from './sandy-chrome/StyleGuide';
 
 export type DefaultKeyboardAction = keyof typeof buildInMenuEntries;
 export type TopLevelMenu = 'Edit' | 'View' | 'Window' | 'Help';
@@ -339,6 +340,12 @@ function getTemplate(
             store.dispatch(setActiveSheet(ACTIVE_SHEET_PLUGINS));
           },
         },
+        {
+          label: 'Flipper style guide',
+          click() {
+            store.dispatch(setStaticView(StyleGuide));
+          },
+        },
         {
           label: 'Toggle Developer Tools',
           accelerator: (function () {