Finalize markdown diagnostics (#161427)

Fixes #146303

This moves the markdown diagnostic support out of `experimental` and to an official feature (however it remains off by default)

extensions/markdown-language-features/server/src/configuration.ts

@@ -16,21 +16,19 @@ interface Settings {
 			};
 		};
 
-		readonly experimental: {
-			readonly validate: {
-				readonly enabled: true;
-				readonly referenceLinks: {
-					readonly enabled: ValidateEnabled;
-				};
-				readonly fragmentLinks: {
-					readonly enabled: ValidateEnabled;
-				};
-				readonly fileLinks: {
-					readonly enabled: ValidateEnabled;
-					readonly markdownFragmentLinks: ValidateEnabled;
-				};
-				readonly ignoreLinks: readonly string[];
+		readonly validate: {
+			readonly enabled: true;
+			readonly referenceLinks: {
+				readonly enabled: ValidateEnabled;
 			};
+			readonly fragmentLinks: {
+				readonly enabled: ValidateEnabled;
+			};
+			readonly fileLinks: {
+				readonly enabled: ValidateEnabled;
+				readonly markdownFragmentLinks: ValidateEnabled;
+			};
+			readonly ignoredLinks: readonly string[];
 		};
 	};
 }
@@ -56,4 +54,4 @@ export class ConfigurationManager extends Disposable {
 	public getSettings(): Settings | undefined {
 		return this._settings;
 	}
-}
+}