chore: add more prop annotations

src/Copy/Copy.svelte

@@ -1,6 +1,20 @@
 <script>
+  /**
+   * Set the feedback text shown after clicking the button
+   * @type {string} [feedback="Copied!"]
+   */
   export let feedback = "Copied!";
+
+  /**
+   * Set the timeout duration (ms) to display feedback text
+   * @type {number} [feedbackTimeout=2000]
+   */
   export let feedbackTimeout = 2000;
+
+  /**
+   * Obtain a reference to the button HTML element
+   * @type {null | HTMLElement} [ref=null]
+   */
   export let ref = null;
 
   import { onMount } from "svelte";
@@ -8,8 +22,6 @@
   let animation = undefined;
   let timeout = undefined;
 
-  $: showFeedback = timeout !== undefined;
-
   onMount(() => {
     return () => {
       clearTimeout(timeout);