style: format app-capture README code examples

Add blank lines between function definitions per PEP 8.

src/window/switcher/app-capture/README.md

@@ -38,9 +38,11 @@ Once compiled, you can easily load the library into any Python script using PyGO
 
 ```python
 import gi
+
 gi.require_version("AppCapture", "1.0")
 from gi.repository import AppCapture
 
+
 def on_frame_ready(capture, address, data, width, height, stride):
     # 'data' is a GLib.Bytes object containing the raw ARGB32 pixel data
     # Convert it to a Cairo Surface or GdkPixbuf
@@ -49,9 +51,11 @@ def on_frame_ready(capture, address, data, width, height, stride):
     # Example: Request the next frame, but wait for damage (0% CPU idle)
     capture.capture_by_handle(address, 300, 168, True)
 
+
 def on_frame_failed(capture, address, reason):
     print(f"Failed to capture {address}: {reason}")
 
+
 # 1. Initialize the capture module
 capture = AppCapture.Capture()
 capture.connect("frame-ready", on_frame_ready)