Add changeset

Author: sissbruecker

.changeset/mighty-chicken-invite.md

@@ -0,0 +1,18 @@
+---
+'@web/test-runner-commands': minor
+---
+
+Added support for holding and releasing keys to the sendKeys command. The command now supports two additional actions `down` and `up` which hold down, or release a key. This effectively allows to hold down modifier keys while pressing other keys, which allows key combinations such as `Shift+Tab`.
+
+@example
+```ts
+  await sendKeys({
+    down: 'Shift',
+  });
+  await sendKeys({
+    press: 'Tab',
+  });
+  await sendKeys({
+    up: 'Shift',
+  });
+```