chore: set hostname for github pages

Author: bennypowers

docs/CNAME

@@ -0,0 +1 @@
+atom-community.io

rocket.config.js

@@ -15,6 +15,7 @@ export default {
   presets: [rocketLaunch(), rocketSearch()],
   markdownTemplateEngine: "njk",
   eleventy(eleventyConfig) {
+    eleventyConfig.addPassthroughCopy(`./**/CNAME`);
     eleventyConfig.addPairedShortcode('markdown', function markdown(content) {
       const md = new markdownIt({ html: true });
       md.use(prism);