chore: install cssbundling rails and set up compilation

spec/dummy/node_modules/yaml/browser/dist/compose/util-map-includes.js

@@ -0,0 +1,17 @@
+import { isScalar } from '../nodes/identity.js';
+
+function mapIncludes(ctx, items, search) {
+    const { uniqueKeys } = ctx.options;
+    if (uniqueKeys === false)
+        return false;
+    const isEqual = typeof uniqueKeys === 'function'
+        ? uniqueKeys
+        : (a, b) => a === b ||
+            (isScalar(a) &&
+                isScalar(b) &&
+                a.value === b.value &&
+                !(a.value === '<<' && ctx.schema.merge));
+    return items.some(pair => isEqual(pair.key, search));
+}
+
+export { mapIncludes };