message: Correct props and typecasting for Header component
diff: @@ -4,10 +4,14 @@ import theme from './theme'
  import {BORDER, COMMON, get, SystemCommonProps, SystemTypographyProps, SystemBorderProps, TYPOGRAPHY} from './constants'
  import {ComponentProps} from './utils/types'
  import sx, {SxProp} from './sx'
  +import * as History from 'history'
  type StyledHeaderItemProps = {full?: boolean} & SystemCommonProps & SxProp
  type StyledHeaderProps = SystemBorderProps & SystemCommonProps & SxProp
  -type StyledHeaderLinkProps = SystemCommonProps & SxProp & SystemTypographyProps & SystemBorderProps & {to?: boolean}
  +type StyledHeaderLinkProps = {to?: History.LocationDescriptor} & SystemCommonProps &
  + SxProp &
  + SystemTypographyProps &
  + SystemBorderProps
  const Header = styled.div<StyledHeaderProps>`
  z-index: 32;
  @@ -44,7 +48,7 @@ const HeaderItem = styled.div<StyledHeaderItemProps>`
  HeaderItem.displayName = 'Header.Item'
  -const HeaderLink = styled.a.attrs(({to}: StyledHeaderLinkProps) => {
  +const HeaderLink = styled.a.attrs<StyledHeaderLinkProps>(({to}) => {
  const isReactRouter = typeof to === 'string'
  if (isReactRouter) {
  // according to their docs, NavLink supports aria-current:
  @@ -53,7 +57,7 @@ const HeaderLink = styled.a.attrs(({to}: StyledHeaderLinkProps) => {
  } else {
  return {}
  }
  -})`
  +})<StyledHeaderLinkProps>`
  font-weight: ${get('fontWeights.bold')};
  color: ${get('colors.text.white')};
  white-space: nowrap;
  