Update the setup quick start doc

Signed-off-by: llhuii <liulinghui@huawei.com>

docs/setup/install.md

@@ -1,4 +1,6 @@
-This guide covers how to install Sedna on an existing Kubernetes environment, i.e. its two main components: [GM(GlobalManager)](/README.md#globalmanager) and [LC(LocalController)](/README.md#localcontroller).
+This guide covers how to install Sedna on an existing Kubernetes environment.
+
+For interested readers, Sedna also has two important components that would be mentioned below, i.e., [GM(GlobalManager)](/README.md#globalmanager) and [LC(LocalController)](/README.md#localcontroller) for workerload generation and maintenance.
 
 If you don't have an existing Kubernetes, you can:
 1) Install Kubernetes by following the [Kubernetes website](https://kubernetes.io/docs/setup/).

docs/setup/quick-start.md

@@ -1,6 +1,6 @@
-There are some ways to setup Sedna:
-- If you have already an existing Kubernetes environment, you can follow [this instruction](./install.md)
-- If you have none Kubernetes environment, you can follow [the all-in-one instruction](./all-in-one.md)
-- If you want to develop Sedna, you can try [the local-up instruction](./local-up.md)
+There are some ways to set up Sedna, depends on your use case:
+- If you have none Kubernetes environment and don't want to install Kubernetes manually, you can follow [the instruction](./all-in-one.md) to install all-in-one Sedna environment.
+- Else you can follow [this instruction](./install.md) to install Sedna on existing Kubernetes cluster.
+- Also [there is a local up script](./local-up.md) which is mainly used for developing Sedna, it boots a local Kubernetes cluster and installs Sedna based on local Sedna repository.
 
-After setup Sedna, you can try [examples](/examples).
+After set up Sedna, you can try out [examples](/examples).