[doc] prerequisite added in quick start (#1808)

docs/manual-CN/1.overview/2.quick-start/1.get-started.md

@@ -2,6 +2,10 @@
 
 本手册将逐步指导您使用 **Nebula Graph**。我们将指导您如何[创建并使用图空间](#创建并使用图空间)，[定义数据的schema](#定义数据的schema)，[插入数据](#插入数据)，[获取数据](#获取数据)，[更新数据](#更新数据)以及[删除数据](#删除数据)。最后我们将指导您如何通过`.ngql`文件来[批量插入](#批量插入)数据。
 
+## 前提条件
+
+在使用 **Nebula Graph** 前，请确保已安装 **Nebula Graph**。您可以选择[编译源码](../../3.build-develop-and-administration/1.build/1.build-source-code.md)，[rpm/deb 包](../../3.build-develop-and-administration/3.deploy-and-administrations/deployment/install-with-rpm-deb.md) 或者 [docker compose](https://github.com/vesoft-inc/nebula-docker-compose) 方式安装 **Nebula Graph**。此处建议使用 [docker compose](https://github.com/vesoft-inc/nebula-docker-compose)。
+
 ## 概述
 
 我们将通过下图中不同点之间的关系向您展示如何使用 **Nebula Graph** 数据库。
@@ -58,13 +62,13 @@ nebula> SHOW SPACES;
 1. 输入以下语句创建 **player** 标签：
 
 ```ngql
-nebula> CREATE TAG player (name string, age int);
+nebula> CREATE TAG player(name string, age int);
 ```
 
 2. 输入以下语句创建 **team** 标签：
 
 ```ngql
-nebula> CREATE TAG team (name string);
+nebula> CREATE TAG team(name string);
 ```
 
 3. 输入以下语句创建 **follow** 边类型：

docs/manual-EN/1.overview/2.quick-start/1.get-started.md

@@ -2,6 +2,10 @@
 
 This guide helps you walk through the process of using **Nebula Graph**. We will show you how to [create and use a graph space](#creating-and-using-a-graph-space), [define the schema for your data](#defining-the-schema-for-your-data), [insert data](#inserting-data), [fetch data](#fetching-data), [update data](#updating-data) and [delete data](#deleting-data). At the end we will show you how to [insert multiple data](#batch-inserting) with a `.ngql` file.
 
+## Prerequisite
+
+Before using **Nebula Graph**, you must install **Nebula Graph** by [installing source code](../../3.build-develop-and-administration/1.build/1.build-source-code.md), [rpm/deb packages](../../3.build-develop-and-administration/3.deploy-and-administrations/deployment/install-with-rpm-deb.md) or [docker compose](https://github.com/vesoft-inc/nebula-docker-compose). It is recommended to install **Nebula Graph** by [docker compose](https://github.com/vesoft-inc/nebula-docker-compose).
+
 ## Overview
 
 We will show you how to use the **Nebula Graph** database based on the relations between different vertices in the following figure:
@@ -58,13 +62,13 @@ You can create tags and edge types by the following steps:
 1. Enter the following statement to create the **player** tag:
 
 ```ngql
-nebula> CREATE TAG player (name string, age int);
+nebula> CREATE TAG player(name string, age int);
 ```
 
 2. Enter the following statement to create the **team** tag:
 
 ```ngql
-nebula> CREATE TAG team (name string);
+nebula> CREATE TAG team(name string);
 ```
 
 3. Enter the following statement to create the **follow** edge type: