remove csharp-syntax-only-extension because vscode omnisharp ships that

extensions/csharp/package.json

@@ -1,23 +0,0 @@
-{
-	"name": "csharp",
-	"version": "0.1.0",
-	"publisher": "vscode",
-	"engines": { "vscode": "*" },
-	"contributes": {
-		"languages": [{
-			"id": "csharp",
-			"extensions": [ ".cs", ".csx" ],
-			"aliases": [ "C#", "csharp" ],
-			"configuration": "./csharp.configuration.json"
-		}],
-		"grammars": [{
-			"language": "csharp",
-			"scopeName": "source.cs",
-			"path": "./syntaxes/csharp.json"
-		}],
-		"jsonValidation": [{
-			"fileMatch": "project.json",
-			"url": "http://json.schemastore.org/project"
-		}]
-	}
-}