Update themes.json Hi! sorry for posting this again but I missed your comments in my last PR https://github.com/vuejs/docs/pull/1847 - I fixed the images links This PR mainly changes the links to new ones and updates the prices & adds links to our plugins as they may be of interest to your users. If there are any problems again, please let me know. Thanks, Mateusz (#987)#988