📝 Update FlexGrid docs

Author: exah

docs/flex-grid.mdx

@@ -11,9 +11,10 @@ import { Box, FlexGrid } from '../src'
 
 # FlexGrid
 
-## Description
+Grid component based on [Flex](/flex) and [Box](/box). 
 
-Grid component based on [Flex](/flex) and [Box](/box).
+Useful if you need to support old browsers without `display: grid`, 
+if don't: use [Grid](/grid) instead.
 
 
 ### Components:
@@ -25,7 +26,7 @@ Grid component based on [Flex](/flex) and [Box](/box).
 - `spacex` — horizontal space
 - `spacey` — vertical space
 
-Possible values for spacing is defined in `theme.space`. See [space docs](https://github.com/exah/pss/blob/master/docs/api.md#space)
+For possible values for spacing see [space docs](https://github.com/exah/pss/blob/master/docs/api.md#space).
 
 
 #### `FlexGrid.Item` — Item / column component, size can be set with props:
@@ -224,6 +225,19 @@ import { FlexGrid } from 'pss-components'
   </FlexGrid>
 </Playground>
 
+### Create your own grid
+
+```js
+const MyGrid = (props) => (
+  <FlexGrid
+    columns={16}
+    space={1}
+    {...props}
+  />
+)
+```
+
+
 ## Props
 
 ### FlexGrid

docs/grid.mdx

@@ -11,7 +11,7 @@ import { Box, Grid } from '../src'
 
 # Grid
 
-[Grid Layout](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Grid_Layout) component, based on [Box](/box) with `display: 'grid'`.
+[Grid Layout](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Grid_Layout) component, based on [Box](/box) with `display: grid`.
 
 - Item conrolled with `column`, `row` prop in `Grid.Item` component
 - [Space](https://github.com/exah/pss/blob/master/docs/api.md#space) between items conrolled with `gap`, `columnGap` and `rowGap` props

docs/input.mdx

@@ -10,8 +10,6 @@ import { Input, Link, ThemeDefaults } from '../src'
 
 # Input
 
-## Description
-
 Based on [Box](/box). Renders `<input>` or `<textarea>` element.
 
 

docs/layout.mdx

@@ -11,8 +11,6 @@ import { Image, Layout, Box } from '../src'
 
 # Layout
 
-## Description
-
 Implements [Media Object](http://www.stubbornella.org/content/2010/06/25/the-media-object-saves-hundreds-of-lines-of-code) with [Flex](/flex) - one of most useful layout components.
 
 Components:

docs/theme-defaults.mdx

@@ -9,8 +9,6 @@ import { ThemeDefaults, Box } from '../src'
 
 # ThemeDefaults
 
-## Description
-
 Change `theme.default` with props.