update readme add install from source (#2561)

* update readme install method

Signed-off-by: Sianao <admin@sianao.cc>

* update chinese install desc

Signed-off-by: Sianao <admin@sianao.cc>

---------

Signed-off-by: Sianao <admin@sianao.cc>

README-zh_CN.md

@@ -61,6 +61,13 @@ Helmfile 是一个声明式Helm Chart管理工具
 
 > 安装后请运行一次 `helmfile init`。 检查[helm-diff](https://github.com/databus23/helm-diff) 等插件安装正确。
 
+**方式4: 源码安装**
+
+依赖: [Go](https://golang.org/dl/)
+
+
+
+` go install github.com/helmfile/helmfile@latest `
 ## 使用
 
 让我们从最简单的 helmfile 开始，逐渐改进它以适应您的用例！

README.md

@@ -75,6 +75,13 @@ For more details, see [run as a container](https://helmfile.readthedocs.io/en/la
 
 > Make sure to run `helmfile init` once after installation. Helmfile uses the [helm-diff](https://github.com/databus23/helm-diff) plugin.
 
+**4: Build from source**
+
+requirements: [Go](https://golang.org/dl/)
+
+
+
+` go install github.com/helmfile/helmfile@latest `
 ## Getting Started
 
 Let's start with a simple `helmfile` and gradually improve it to fit your use-case!