Add documentation for registering service at macOS (#54)

* Fix typos in filenames
* Fix letter cases and add space between words
* Add documentations for macOS service
* Revert SOCKS protocol cases change
* Capitalise the first letter of indexes

guide/network/install-as-a-macos-service.md

@@ -0,0 +1,33 @@
+# 安装为 macOS 服务
+
+下载并安装 [serviceman](https://webinstall.dev/serviceman)。
+
+打开终端，运行如下命令注册服务：
+
+```bash
+# 使用配置文件注册 easytier 服务
+sudo serviceman add -name easytier -system \
+--workdir /var/log/easytier \
+-groupname wheel -username root \
+-cap-net-bind \
+-- easytier-core -c ~/.config/easytier.toml
+
+# 不使用配置文件注册 easytier 服务
+sudo serviceman add -name easytier -system \
+--workdir /var/log/easytier \
+-groupname wheel -username root \
+-cap-net-bind \
+-- easytier-core --ipv4 x.x.x.x --network-name xxx --network-secret yyy --peers tcp://peer_host:11010
+```
+
+启动 easytier 服务：
+
+```bash
+sudo serviceman start easytier
+```
+
+关闭 easytier 服务：
+
+```bash
+sudo serviceman stop easytier
+```