feat(truncate): add text truncation component and action

actions/truncate.js

@@ -0,0 +1,24 @@
+/**
+ * Svelte action that applies single-line text truncation to an element
+ * @param {HTMLElement} node
+ * @param {{ direction?: "end" | "front" }} params
+ * @example
+ * <script>
+ *   import { truncate } from "carbon-components-svelte/actions";
+ * </script>
+ *
+ * <h1 use:truncate>...</h1>
+ */
+export function truncate(node, params = {}) {
+  function toggleClass(front = false) {
+    node.className = `bx--text-truncate--${front ? "front" : "end"}`;
+  }
+
+  toggleClass(params.direction === "front");
+
+  return {
+    update(params) {
+      toggleClass(params.direction === "front");
+    },
+  };
+}