refactor: move test/ and yarn to repo root

Also lint and format entire repo, beyond just wowchemy/ dir

URL encode `(` and `)` in `[#MadeWithWowchemy](...(..)...)` in Readme.md for Prettier

.prettierrc.js

@@ -0,0 +1,17 @@
+'use strict';
+
+module.exports = {
+  bracketSpacing: false,
+  singleQuote: true,
+  jsxBracketSameLine: true,
+  trailingComma: 'all',
+  printWidth: 120,
+  overrides: [
+    {
+      files: ['*.html'],
+      options: {
+        parser: 'go-template',
+      },
+    },
+  ],
+};