grammar

docs/src/pages/configurations/theming/index.md

@@ -124,7 +124,7 @@ export default create({
 
 Some addons require specific theme variables that a Storybook user must add. If you share your theme with the community make sure to support the official and other popular addons so your users have a consistent experience.
 
-For example, the popular Actions addon uses [react-inspector](https://github.com/xyc/react-inspector/blob/master/src/styles/themes/chromeLight.js) which has themes of it's own. Supply additional theme variables to style it like so:
+For example, the popular Actions addon uses [react-inspector](https://github.com/xyc/react-inspector/blob/master/src/styles/themes/chromeLight.js) which has themes of its own. Supply additional theme variables to style it like so:
 
 ```js
 addonActionsTheme: {