message: print props in docs
diff: +import {printProps, COMMON, LAYOUT, TYPOGRAPHY, FLEX_CONTAINER, FLEX_ITEM, POSITION} from '../../../src/system-props.js'
  +import {Text} from '../../..'
  +
  # System Props
  @@ -5,13 +8,15 @@ Primer Components utilize what we call "system props" to apply a standard set of
  To check which system props each component includes, check the documentation for that component.
  +
  +
  ### System Prop Categories
  | Category | Included Props | styled-system docs |
  |-----|--------|--------|
  -| `COMMON`| space, color | [styled-system core docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#core) |
  -| `TYPOGRAPHY`| fontFamily, fontSize, fontWeight, lineHeight & all `COMMON` props | [styled-system typography docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#typography) |
  -| `LAYOUT` | display, size, width, height, minWidth, minHeight, <br/> maxWidth, maxHeight, verticalAlign & all `COMMON` props | [styled-system layout docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#layout) <br/> [styled-system core docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#core) |
  -| `POSITION` | position, zIndex, top, right, bottom, left | [styled-system position docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#position)
  -| `FLEX_CONTAINER` | flex, flexBasis, flexDirection, flexWrap, <br/> alignContent, alignItems, justifyContent, <br/> justifyItems, order & all `LAYOUT` props | [styled-system flexbox docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#flexbox) |
  -| `FLEX_ITEM` | justifySelf, alignSelf & all `LAYOUT` props | [styled-system flexbox docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#flexbox) |
  +| `COMMON`| <Text children={printProps(COMMON)} /> | [styled-system core docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#core) |
  +| `TYPOGRAPHY`| <Text children={printProps(TYPOGRAPHY)} /> | [styled-system typography docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#typography) |
  +| `LAYOUT` | <Text children={printProps(LAYOUT)} /> | [styled-system layout docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#layout) <br/> [styled-system misc docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#misc) |
  +| `POSITION` | <Text children={printProps(POSITION)} />| [styled-system position docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#position)
  +| `FLEX_CONTAINER` | <Text children={printProps(FLEX_CONTAINER)} /> | [styled-system flexbox docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#flexbox) |
  +| `FLEX_ITEM` | <Text children={printProps(FLEX_ITEM)} /> | [styled-system flexbox docs](https://github.com/jxnblk/styled-system/blob/master/docs/table.md#flexbox) |
  