Include C# textmate grammar. Fixes #19469

extensions/csharp/OSSREADME.json

@@ -0,0 +1,10 @@
+// ATTENTION - THIS DIRECTORY CONTAINS THIRD PARTY OPEN SOURCE MATERIALS:
+[
+	{
+		"name": "dotnet/csharp-tmLanguage",
+		"version": "0.1.0",
+		"license": "MIT",
+		"repositoryURL": "https://github.com/dotnet/csharp-tmLanguage",
+		"description": "The file syntaxes/csharp.tmLanguage.json was derived from https://github.com/dotnet/csharp-tmLanguage"
+	}
+]

extensions/csharp/language-configuration.json

@@ -0,0 +1,27 @@
+{
+	"comments": {
+		"lineComment": "//",
+		"blockComment": ["/*", "*/"]
+	},
+	"brackets": [
+		["{", "}"],
+		["[", "]"],
+		["(", ")"]
+	],
+	"autoClosingPairs": [
+		["{", "}"],
+		["[", "]"],
+		["(", ")"],
+		{ "open": "'", "close": "'", "notIn": ["string", "comment"] },
+		{ "open": "\"", "close": "\"", "notIn": ["string", "comment"] },
+		{ "open": "/*", "close": " */", "notIn": ["string"] }
+	],
+	"surroundingPairs": [
+		["{", "}"],
+		["[", "]"],
+		["(", ")"],
+		["<", ">"],
+		["'", "'"],
+		["\"", "\""]
+	]
+}

extensions/csharp/package.json

@@ -0,0 +1,35 @@
+{
+  "name": "csharp",
+  "version": "0.1.0",
+  "publisher": "vscode",
+  "engines": {
+    "vscode": "0.10.x"
+  },
+  "scripts": {
+		"update-grammar": "node ../../build/npm/update-grammar.js dotnet/csharp-tmLanguage grammars/csharp.tmLanguage ./syntaxes/csharp.tmLanguage.json"
+	},
+
+  "contributes": {
+    "languages": [
+      {
+        "id": "csharp",
+        "extensions": [
+          ".cs",
+          ".csx"
+        ],
+        "aliases": [
+          "C#",
+          "csharp"
+        ],
+        "configuration": "./language-configuration.json"
+      }
+    ],
+    "grammars": [
+      {
+        "language": "csharp",
+        "scopeName": "source.cs",
+        "path": "./syntaxes/csharp.tmLanguage.json"
+      }
+    ]
+  }
+}