Make the webpack config work for us

This moves the babel and postcss configs into the webpack config for ease of maintenance (and because we need variations of them). The typescript config is left outside the webpack config for IDEs to pick it up.

tsconfig.json

@@ -0,0 +1,19 @@
+{
+  "compilerOptions": {
+    "experimentalDecorators": true,
+    "emitDecoratorMetadata": true,
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "target": "es2016",
+    "noImplicitAny": false,
+    "sourceMap": false,
+    "outDir": "./lib",
+    "declaration": true,
+    "types": [
+      "node"
+    ]
+  },
+  "include": [
+    "./src/**/*.ts"
+  ]
+}