Control allow index per environment, default to false

src/docs-assembler/Building/AssemblerBuilder.cs

@@ -58,7 +58,7 @@ private async Task BuildAsync(Checkout checkout, PublishEnvironment environment,
 			StaticUrlPathPrefix = environment.PathPrefix,
 			UrlPathPrefix = pathPrefix,
 			Force = true,
-			AllowIndexing = true
+			AllowIndexing = environment.AllowIndexing
 		};
 
 		var set = new DocumentationSet(buildContext, logger, crossLinkResolver);

src/docs-assembler/Configuration/AssemblyConfiguration.cs

@@ -89,4 +89,7 @@ public record PublishEnvironment
 
 	[YamlMember(Alias = "path_prefix")]
 	public string? PathPrefix { get; set; } = string.Empty;
+
+	[YamlMember(Alias = "allow_indexing")]
+	public bool AllowIndexing { get; set; }
 }

src/docs-assembler/assembler.yml

@@ -2,6 +2,7 @@ environments:
   production:
     uri: https://elastic.co
     path_prefix: docs
+    allow_indexing: false
   staging:
     uri: https://staging-website.elastic.co
     path_prefix: docs