enh(csharp) Added support for the new scoped keyword in C#

CHANGES.md

@@ -2,6 +2,7 @@
 
 Grammars:
 
+- enh(csharp) Added support for the new `scoped` keyword in C# (#3571) [David Pine][]
 - enh(scala) add `transparent` keyword [Matt Bovel][]
 - fix(rust) highlight types immediately preceeding `::` (#3540) [Josh Goebel][] 
 - Added 3rd party Apex grammar to SUPPORTED_LANGUAGES (#3546) [David Schach][]

src/languages/csharp.js

@@ -2,7 +2,7 @@
 Language: C#
 Author: Jason Diamond <jason@diamond.name>
 Contributor: Nicolas LLOBERA <nllobera@gmail.com>, Pieter Vantorre <pietervantorre@gmail.com>, David Pine <david.pine@microsoft.com>
-Website: https://docs.microsoft.com/en-us/dotnet/csharp/
+Website: https://docs.microsoft.com/dotnet/csharp/
 Category: common
 */
 
@@ -93,6 +93,7 @@ export default function(hljs) {
     'record',
     'ref',
     'return',
+    'scoped',
     'sealed',
     'sizeof',
     'stackalloc',

test/markup/csharp/scoped.expect.txt

@@ -0,0 +1 @@
+<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">ref</span> T <span class="hljs-title">AsRef</span>&lt;<span class="hljs-title">T</span>&gt;(<span class="hljs-params"><span class="hljs-keyword">scoped</span> <span class="hljs-keyword">in</span> T source</span>)</span>;

test/markup/csharp/scoped.txt

@@ -0,0 +1 @@
+public static ref T AsRef<T>(scoped in T source);