adding arduino examples for DHT11, blink, and temperature sensor

week3/examples/Projects/DHT11_Sensor/.vscode/extensions.json

@@ -0,0 +1,11 @@
+{
+    // See http://go.microsoft.com/fwlink/?LinkId=827846
+    // for the documentation about the extensions.json format
+    "recommendations": [
+        "platformio.platformio-ide"
+    ],
+    "unwantedRecommendations": [
+        "ms-vscode.cpptools-extension-pack",
+        "pioarduino.pioarduino-ide"
+    ]
+}