fix: remove trailing blank line in pfe-assets plugin

Fixes padded-blocks lint error.

Assisted-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: bennypowers

docs/_plugins/pfe-assets.cjs

@@ -85,6 +85,5 @@ module.exports = {
     // The demo files are written primarily for the dev SPA (`npm start`),
     // so here we transform the paths found in those files to match the docs site's file structure
     eleventyConfig.addTransform('demo-paths', demoPaths);
-
   },
 };