Examples: placeholders instead of the street name and the Envoy serial

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/make_example_pages.py

@@ -315,6 +315,7 @@ def el(type, x, y, font='Normal', **kw):
     return e
 
 
+# Placeholders: put your own entity ids here (the Envoy ones contain its serial number)
 ENVOY = 'sensor.envoy_000000000000_'
 pages = {
     # 1. Weather clock: large clock, weather icon, outside humidity and temperature