Clarify that selectedrows is used like an array

### Type of issue

Missing information

### Description

Clarify that selectedrows is used like an array. The sxample in the documentation doesn't make it very clear as someone new to windows forms.

it can have something like this: The property `DataGridView.SelectedRows `is an array, and each index in this array corresponds to one row that has been selected in the datagridview. This property is accessed similarly to an array, for example, as `DataGridView.SelectedRows[0]` where 0 is the index of the array.

### Page URL

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

### Content source URL

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

### Document Version Independent Id

54277d13-617f-cda8-33d1-1a9bee718bf6

### Article author

@dotnet-bot