Example missing code

### Type of issue

Code doesn't work

### Description

PrintDialog.Document Property
https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.printdialog.document?view=windowsdesktop-8.0

Missing the following code:

this.button1.Click += new System.EventHandler(this.button1_Click);

docToPrint.PrintPage += new PrintPageEventHandler
(this.document_PrintPage);

[Enter feedback here]

### Page URL

https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.printdialog.document?view=windowsdesktop-8.0

### Content source URL

https://github.com/dotnet/dotnet-api-docs/blob/main/xml/System.Windows.Forms/PrintDialog.xml

### Document Version Independent Id

c8777944-785f-94fd-e54c-40053d17d0a3

### Article author

@dotnet-bot