update readme (#7)

Signed-off-by: veophi <vec.g.sun@gmail.com>

README.md

@@ -1,2 +1,50 @@
-# rollouts
-Enhanced Rollouts features for application automation.
+# Rollouts
+[![License](https://img.shields.io/badge/license-Apache%202-4EB1BA.svg)](https://www.apache.org/licenses/LICENSE-2.0.html)
+
+## Introduction
+
+Kruise Rollouts is a **Bypass** component which provides advanced deployment capabilities such as canary, traffic routing, and progressive delivery features, for a series of Kubernetes workloads, such as Deployment and CloneSet.
+
+![arch](docs/images/rollout-arch.jpg)
+
+## Why Kruise Rollouts?
+- **Functionality**：
+    - Support multi-batch delivery for Deployment/CloneSet.
+    - Support Nginx/ALB/Istio traffic routing control during rollout.
+
+- **Flexibility**:
+    - Support scaling up/down to workloads during rollout.
+    - Can be applied to newly-created or existing workload objects directly;
+    - Can be ridden out of at any time when you needn't it without consideration of unavailable workloads and traffic problems.
+    - Can cooperate with other native/third-part Kubernetes controllers/operators, such as HPA and WorkloadSpread.
+
+- **Non-Invasion**:
+    - Does not invade native workload controllers.
+    - Does not replace user-defined workload and traffic configurations.
+
+- **Extensibility**:
+    - Easily extend to other traffic routing types, or workload types via plugin codes.
+
+- **Easy-integration**:
+    - Easily integrate with classic or GitOps-style Kubernetes-based PaaS.
+
+## Documents
+Coming soon ...
+
+## Community
+
+Active communication channels:
+
+- Slack: [OpenKruise channel](https://kubernetes.slack.com/channels/openkruise) (*English*)
+- DingTalk：Search GroupID `23330762` (*Chinese*)
+- WeChat: Search User `openkruise` and let the robot invite you (*Chinese*)
+- Bi-weekly Community Meeting (APAC, *Chinese*):
+  - Thursday 19:00 GMT+8 (Asia/Shanghai), [Calendar](https://calendar.google.com/calendar/u/2?cid=MjdtbDZucXA2bjVpNTFyYTNpazV2dW8ybHNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ)
+  - [Meeting Link(zoom)](https://us02web.zoom.us/j/87059136652?pwd=NlI4UThFWXVRZkxIU0dtR1NINncrQT09)
+  - [Notes and agenda](https://shimo.im/docs/gXqmeQOYBehZ4vqo)
+- Bi-weekly Community Meeting (*English*): TODO
+
+## License
+
+Kruise rollouts is licensed under the Apache License, Version 2.0. See [LICENSE](./LICENSE.md) for the full license text. 
+