style: unify quote style in rollup config

Author: cotes2020

rollup.config.js

@@ -11,7 +11,7 @@ const DIST = 'assets/js/dist';
 const banner = `/*!
  * ${pkg.name} v${pkg.version} | © ${pkg.since} ${pkg.author} | ${pkg.license} Licensed | ${pkg.homepage}
  */`;
-const frontmatter = `---\npermalink: /:basename\n---\n`;
+const frontmatter = '---\npermalink: /:basename\n---\n';
 const isProd = process.env.BUILD === 'production';
 
 let hasWatched = false;