Add header for game list (#3)

Co-authored-by: Maxime Adler <madler@sqli.com>
Reviewed-on: #3

src/GameIdeas/GameIdeas.Shared/Dto/LoginDto.cs

@@ -0,0 +1,7 @@
+namespace GameIdeas.Shared.Dto;
+
+public class LoginDto
+{
+    public string? Username { get; set; }
+    public string? Password { get; set; }
+}