Document Container grow / shrink properties

Summary: For some reason, the most important container property grow (and shrink) wasn't in the docs. Added that

Reviewed By: antonk52

Differential Revision: D36697072

fbshipit-source-id: 45dd0351e2a94d31972d57a9f006cd06a0d37c4e

desktop/flipper-ui-core/src/sandy-chrome/DesignComponentDemos.tsx

@@ -77,6 +77,16 @@ const demos: PreviewProps[] = [
     title: 'Layout.Container',
     description: `Layout.Container can be used to organize the UI in regions. It takes care of paddings and borders. Children will be arranged vertically. Use Layout.Horizontal instead for arranging children horizontally. If you need a margin on this component, try to wrap it in other Layout component instead.`,
     props: [
+      [
+        'grow',
+        'boolean (false)',
+        "Should the container use all available size (true), or rather take the size of it's content? (false).",
+      ],
+      [
+        'shrink',
+        'boolean (false)',
+        'Is the container allowed to become smaller than the space the children need? If e.g. text content needs to be ellipsed, this should be set to true',
+      ],
       ['rounded', 'boolean (false)', 'Make the corners rounded'],
       [
         'padv / padh / pad',