fix: portal fails gracefully if target doesn't exist

Author: jacob-8

src/lib/actions/portal.ts

@@ -2,14 +2,18 @@
  * Usage: `<div use:portal>` or `<div use:portal={'#direction'}>`, add `hidden` if SSR rendered (requires updating action with node.hidden = false and true)
  */
 export function portal(node: HTMLElement, target = 'body') {
-  const portal = document.createElement('div');
-  document.querySelector(target).appendChild(portal);
-  portal.appendChild(node);
+  const target_div = document.querySelector(target)
+  if (!target_div)
+    return
+
+  const portal = document.createElement('div')
+  target_div.appendChild(portal)
+  portal.appendChild(node)
 
   return {
     destroy() {
-      portal.parentElement.removeChild(portal);
+      portal.parentElement.removeChild(portal)
     },
-  };
+  }
 }
 // from https://github.com/romkor/svelte-portal