message: Add 'ButtonGroup' to 'index.d.ts'
diff: @@ -126,6 +126,7 @@ declare module '@primer/components' {
  export const ButtonPrimary: React.FunctionComponent<ButtonProps>
  export const ButtonOutline: React.FunctionComponent<ButtonProps>
  export const ButtonDanger: React.FunctionComponent<ButtonProps>
  + export const ButtonGroup: React.FunctionComponent<BoxProps>
  export const Button: React.FunctionComponent<ButtonProps>
  export interface AvatarProps extends CommonProps, Omit<React.ImgHTMLAttributes<HTMLImageElement>, 'color'> {
  @@ -363,6 +364,11 @@ declare module '@primer/components/src/ButtonOutline' {
  export default ButtonOutline
  }
  +declare module '@primer/components/src/ButtonGroup' {
  + import {ButtonGroup} from '@primer/components'
  + export default ButtonGroup
  +}
  +
  declare module '@primer/components/src/Button' {
  import {Button} from '@primer/components'
  export default Button
  