fix(template js): fix query selector for nested articles and primary color default

Author: nkint

template/src/index.js

@@ -78,15 +78,15 @@ function addProgress(config) {
 		return;
 	}
 
-	const articles = [...document.getElementsByTagName('article')];
+	const articles = [...document.querySelectorAll()('main > article')];
 
 	if(config.progress === 'line') {
 		articles.forEach((article, index) => {
 			const line = document.createElement('div');
 			line.classList.add("progress-line");
 			article.appendChild(line);
 
-			line.style.backgroundColor = 'var(--primary-color)';
+			line.style.backgroundColor = 'var(--primary-color, #000)';
 
 			line.style.height = '3px';
 			line.style.position = 'absolute';