Update the docs for installing yq.

Author: cotes2020

Diff for: README.md

@@ -58,7 +58,7 @@ $ bundle install
 
 `bundle` will automatically install all the dependencies specified by `Gemfile`.
 
-What's more, in order to generate some extra files (*categories*, *tags* and *last modified list*), we need to use some tool scripts. If your machine is running Debian or macOS, make sure that [GNU coreutils](https://www.gnu.org/software/coreutils/) is installed. Otherwise, install by:
+In order to generate some extra files (*categories*, *tags* and *last modified list*), we need to use some tool scripts. And they require dependency package [yq](https://github.com/mikefarah/yq#install) to be installed. What's more, if your machine is running Debian or macOS, you also need to install [GNU coreutils](https://www.gnu.org/software/coreutils/):
 
 - Debian
 
@@ -187,4 +187,4 @@ If you enjoy this theme or find it helpful, please consider becoming my sponsor,
 
 ## License
 
-This work is published under [MIT](https://github.com/cotes2020/jekyll-theme-chirpy/blob/master/LICENSE) License.
+This work is published under [MIT](https://github.com/cotes2020/jekyll-theme-chirpy/blob/master/LICENSE) License.

Diff for: _posts/2019-08-09-getting-started.md

@@ -28,7 +28,7 @@ $ bundle install
 
 `bundle` will automatically install all the dependencies specified by `Gemfile`.
 
-What's more, in order to generate some extra files (*categories*, *tags* and *last modified list*), we need to use some tool scripts. If your machine is running Debian or macOS, make sure that [GNU coreutils](https://www.gnu.org/software/coreutils/) is installed. Otherwise, install by:
+In order to generate some extra files (*categories*, *tags* and *last modified list*), we need to use some tool scripts. And they require dependency package [yq](https://github.com/mikefarah/yq#install) to be installed. What's more, if your machine is running Debian or macOS, you also need to install [GNU coreutils](https://www.gnu.org/software/coreutils/):
 
 - Debian
 

Diff for: docs/README_zh-CN.md

@@ -61,7 +61,7 @@ $ bundle install
 
 `bundle` 会自动安装 `Gemfile` 内指定的依赖插件。
 
-另外，为了生成一些额外的文件（ Post 的分类、标签以及更新时间列表），需要用到一些脚本工具。如果你电脑的操作系统是 Debian 或者 macOS，请确保已经安装了[GNU coreutils](https://www.gnu.org/software/coreutils/)，否则，通过以下方式完成安装：
+为了生成一些额外的文件（Post 的分类、标签以及更新时间列表），需要用到一些脚本工具。而它们需要安装依赖包 [yq](https://github.com/mikefarah/yq#install)。另外，如果你电脑的操作系统是 Debian 或者 macOS，还需安装 [GNU coreutils](https://www.gnu.org/software/coreutils/)：
 
 - Debian