Add workspace suggested extensions

Author: eliericha

.vscode/extensions.json

@@ -0,0 +1,9 @@
+{
+   "recommendations": [
+      "ms-python.black-formatter",
+      "ms-python.flake8",
+      "editorconfig.editorconfig",
+      "dbaeumer.vscode-eslint",
+      "esbenp.prettier-vscode"
+   ]
+}