Remove theme ui gatsby plugin

Author: kpfromer

gatsby-config.js

@@ -54,8 +54,7 @@ module.exports = {
     },
     `gatsby-transformer-remark`,
     `gatsby-plugin-preact`,
-    `gatsby-plugin-emotion`,
-    `gatsby-plugin-theme-ui`
+    `gatsby-plugin-emotion`
     // this (optional) plugin enables Progressive Web App + Offline functionality
     // To learn more, visit: https://gatsby.dev/offline
     // `gatsby-plugin-offline`,