fix(api): missing transparent flag on WindowOptions (#1764)

Author: lucasfernog

.changes/api-transparent-window.md

@@ -0,0 +1,5 @@
+---
+"api": patch
+---
+
+Adds `transparent?: boolean` to the `WindowOptions` interface.

tooling/api/src/window.ts

@@ -687,6 +687,8 @@ export interface WindowOptions {
   title?: string
   /** Whether the window is in fullscreen mode or not. */
   fullscreen?: boolean
+  /** Whether the window is transparent or not. */
+  transparent?: boolean
   /** Whether the window should be maximized upon creation or not. */
   maximized?: boolean
   /** Whether the window should be immediately visible upon creation or not. */