Linting, so much linting

I installed and configured stylelint and eslint, and added an editorconfig as well as a vscode recommended extensions file.

The reason the diff is so large is I ran the linters and fixed all the linting issues.

.vscode/extensions.json

@@ -0,0 +1,6 @@
+{
+  "recommendations": [
+    "dbaeumer.vscode-eslint",
+    "stylelint.vscode-stylelint"
+  ]
+}