:bug: fixed margin for intersection handler

vue-theme/src/pages/list.vue

 
             console.warn('setting up intersection handler for:', this.type)
             const footerEl = document.querySelector(".footer-wrapper footer")
-            console.warn('attach to: ',footerEl)
+            console.warn('found el: ',footerEl)
             if(!footerEl) return
+            console.warn('attach to: ',footerEl)
 
             const onIntersect = (entries, observer) => {
                 console.log('intersection handler fired...')
             }
             const settings = {
                 root: footerEl,
-                rootMargin: '-20px 0 0 0',
+                rootMargin: '-20px 0px 0px 0px',
                 threshold: 1.0
             }
             this.observer = new IntersectionObserver(onIntersect, settings)