docs: added stdlib Index

Signed-off-by: Sam Alba <sam.alba@gmail.com>

docs/reference/universe/README.md

@@ -0,0 +1,28 @@
+# Index
+
+- [aws](./aws/README.md)
+- [aws/ecr](./aws/ecr.md)
+- [aws/rds](./aws/rds.md)
+- [git](./git.md)
+- [kubernetes](./kubernetes/README.md)
+- [terraform](./terraform.md)
+- [random](./random.md)
+- [aws/ecs](./aws/ecs.md)
+- [aws/s3](./aws/s3.md)
+- [dagger/op](./dagger/op.md)
+- [gcp](./gcp/README.md)
+- [go](./go.md)
+- [js/yarn](./js/yarn.md)
+- [kubernetes/helm](./kubernetes/helm.md)
+- [docker](./docker.md)
+- [gcp/gcr](./gcp/gcr.md)
+- [gcp/gke](./gcp/gke.md)
+- [io](./io.md)
+- [kubernetes/kustomize](./kubernetes/kustomize.md)
+- [os](./os.md)
+- [alpine](./alpine.md)
+- [aws/cloudformation](./aws/cloudformation.md)
+- [aws/eks](./aws/eks.md)
+- [aws/elb](./aws/elb.md)
+- [dagger](./dagger/README.md)
+- [netlify](./netlify.md)