Configure valid docset dev langs for docs-markdown extension (dotnet#16986)

Author: scottaddie

.vscode/settings.json

@@ -3,4 +3,27 @@
     "[markdown]": {
         "files.trimTrailingWhitespace": false
     },
+    "markdown.docsetLanguages": [
+        ".NET Core CLI",
+        "Azure CLI",
+        "Bash",
+        "C#",
+        "CSS",
+        "Dockerfile",
+        "Gradle",
+        "HTML",
+        "Ini",
+        "JSON",
+        "Java",
+        "JavaScript",
+        "Markdown",
+        "Nginx",
+        "PowerShell",
+        "Protocol Buffers",
+        "Razor CSHTML",
+        "SQL",
+        "TypeScript",
+        "XML",
+        "YAML"
+    ]
 }