Improve documentation for platform prefixes on Windows

[nickrandolph]

What would you like clarification on

The docs on platform specific xaml indicates that the "win" prefix can be used to indicate elements/attributes specific to windows. This only appears to work for elements, not for attributes.
Docs should be updated to illustrates workarounds:

• duplicate elements showing win/not_win options
• set default property value for win

Concern

Clarification of capabilities

Affected platforms

Windows (WinAppSDK)

Any feedback?

No response