Update AV1523 guideline

Split from #298.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Dennis Doomen

_rules/1523.md

@@ -4,32 +4,23 @@ rule_category: maintainability
 title: Favor object and collection initializers over separate statements
 severity: 2
 ---
-Instead of:
-
-	var startInfo = new ProcessStartInfo("myapp.exe");
-	startInfo.StandardOutput = Console.Output;
-	startInfo.UseShellExecute = true;
-
-	var countries = new List();
-	countries.Add("Netherlands");
-	countries.Add("United States");
-
-	var countryLookupTable = new Dictionary<string, string>();
-	countryLookupTable.Add("NL", "Netherlands");
-	countryLookupTable.Add("US", "United States");
-
-Use [Object and Collection Initializers](http://msdn.microsoft.com/en-us/library/bb384062.aspx):
+Use [Object and Collection Initializers](https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/object-and-collection-initializers):
 
 	var startInfo = new ProcessStartInfo("myapp.exe")
 	{
 		StandardOutput = Console.Output,
 		UseShellExecute = true
 	};
 
-	var countries = new List { "Netherlands", "United States" };
+	var countries = new List<string> { "Netherlands", "United States" };
 
 	var countryLookupTable = new Dictionary<string, string>
 	{
 		["NL"] = "Netherlands",
 		["US"] = "United States"
 	};
+
+This also applies to arrays and the spread operator (C# 12+):
+
+	string[] moreCountries = ["Belgium", "Germany"];
+	string[] allCountries = [..countries, ..moreCountries];