❌ escape key support

ref #26

src/components/AddTrackModal.svelte

@@ -19,6 +19,14 @@
   $: isTracklengthValid = tracklength <= 0;
   $: trackMintimevalid = track_min_duration >= 0;
   $: createbtnenabled = !isTracknameValid && !isTracklengthValid;
+  (function () {
+    document.onkeydown = function (e) {
+      e = e || window.event;
+      if (e.key === "Escape") {
+        modal_open = false;
+      }
+    };
+  })();
   function submit() {
     if (processed_last_submit === true) {
       processed_last_submit = false;