Speed up load time

manifest.json

@@ -13,7 +13,7 @@
 	],
 	"content_scripts": [
 		{
-			"run_at": "document_end",
+			"run_at": "document_start",
 			"matches": [
 				"https://github.com/*/*",
 				"https://gist.github.com/*/*"

src/content.js

@@ -1,6 +1,6 @@
 // Inject empty style element for us to use
 const style = document.createElement('style');
-document.body.appendChild(style);
+document.addEventListener('DOMContentLoaded', () => document.body.appendChild(style));
 
 // Set tab size styles
 const setTabSizeStyles = size => style.innerHTML = `