update metric-hide-value.py

doc/gui/examples/controls/metric-don't-show-value.py → doc/gui/examples/controls/metric-hide-value.py

@@ -16,7 +16,7 @@
 from taipy.gui import Gui
 
 page = """
-<|90|metric|show_value=false|>
+<|90|metric|don't show_value|>
 """