Love the idea of reusable themes, I was heading into the same end result with my Gatsby starters & reusable React components which most are published as npm packages, days after Gatsby themes were available, I went ahead & converted my dev portfolio starter into a theme, making it more customizable & easier to use, here's the link of the theme if anyone wants to try it out: https://www.npmjs.com/package/gatsby-theme-portfolio
