Add clarification that FileInfo.MoveTo modifies its FullName to point to the new file

### Type of issue

Missing information

### Description

Currently it's not clear if after calling `MoveTo`, does the `FileInfo` still point to the old path or the new one. In this example:

```cs
var file = new FileInfo(@"D:\Temp\test.txt");
file.MoveTo(@"D:\Temp\test2.txt");

Console.WriteLine(file.FullName); // Now prints D:\Temp\test2.txt
Console.WriteLine(file.Exists); // Prints true still
```

It's quite a surprising behavior for me. I thought the FileInfo stayed the same.

### Page URL

https://learn.microsoft.com/en-us/dotnet/api/system.io.fileinfo?view=net-10.0

### Content source URL

https://github.com/dotnet/dotnet-api-docs/blob/main/xml/System.IO/FileInfo.xml

### Document Version Independent Id

8ff2dee9-0ff5-4e0e-e58e-c2426ae7de11

### Platform Id

7223a61b-29bf-4e03-57b1-2da74b5bf9a6

### Article author

@dotnet-bot