Refactor the README (#1145)

Author: Vincent

Diff for: README.md

@@ -1,13 +1,29 @@
 # Knative Operator
 
+[![go.dev reference](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white)](https://pkg.go.dev/github.com/knative/operator)
+[![Go Report Card](https://goreportcard.com/badge/knative/operator)](https://goreportcard.com/report/knative/operator)
+[![Releases](https://img.shields.io/github/release-pre/knative/operator.svg?sort=semver)](https://github.com/knative/operator/releases)
+[![LICENSE](https://img.shields.io/github/license/knative/operator.svg)](https://github.com/knative/operator/blob/main/LICENSE)
+[![Slack Status](https://img.shields.io/badge/slack-join_chat-white.svg?logo=slack&style=social)](https://knative.slack.com)
+[![codecov](https://codecov.io/gh/knative/operator/branch/main/graph/badge.svg)](https://codecov.io/gh/knative/operator)
+[![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/5913/badge)](https://bestpractices.coreinfrastructure.org/projects/5913)
+
 The Knative Operator defines custom resources for the
-[Knative](https://knative.dev/) components, [serving](config/300-serving.yaml)
-and [eventing](config/300-eventing.yaml), enabling users to configure, install,
+[Knative](https://knative.dev/) components, including serving and eventing, enabling users to configure, install,
 upgrade and maintain these components over their lifecycle through a simple API.
 
 Details:
 
-- [Installation](docs/installation.md)
-- [Configuration](docs/configuration.md)
+- [Installation](https://knative.dev/docs/install/operator/knative-with-operators/)
+- [Serving Configuration](https://knative.dev/docs/install/operator/configuring-serving-cr/)
+- [Eventing Configuration](https://knative.dev/docs/install/operator/configuring-eventing-cr/)
+- [Upgrade](docs/upgrade.md)
 - [Development](docs/development.md)
 - [Release](docs/release.md)
+
+For documentation on using Knative Operator, see the
+[Knative operator section](https://knative.dev/docs/install/operator/knative-with-operators/) of the
+[Knative documentation site](https://www.knative.dev/docs).
+
+If you are interested in contributing, see [CONTRIBUTING.md](./CONTRIBUTING.md)
+and [DEVELOPMENT.md](./DEVELOPMENT.md).