Added extension recommendation as otherwise the VSCode solution will now work

Author: Aragas

src/Bannerlord.Module.CSharp/.vscode/extensions.json

@@ -0,0 +1,6 @@
+{
+    "recommendations": [
+        "ms-dotnettools.csharp",
+        "ms-dotnettools.csdevkit"
+    ]
+}

src/Bannerlord.Module.Sdk.CSharp/.vscode/extensions.json

@@ -0,0 +1,6 @@
+{
+    "recommendations": [
+        "ms-dotnettools.csharp",
+        "ms-dotnettools.csdevkit"
+    ]
+}