doc: update readme of addon viewport
doc: update readme of addon viewport

- about configure section
storybooks/react-storybook,storybooks/react-storybook,storybooks/storybook,storybooks/storybook,kadirahq/react-storybook,storybooks/react-storybook,storybooks/storybook,storybooks/storybook,storybooks/react-storybook,kadirahq/react-storybook,storybooks/storybook,storybooks/storybook,storybooks/storybook