refactor: remove system directory from meta_plugin

src/meta_plugin/mod.rs

@@ -0,0 +1,13 @@
+pub mod cwd;
+pub mod user;
+pub mod shell;
+pub mod shell_pid;
+pub mod keep_pid;
+pub mod hostname;
+
+pub use cwd::CwdMetaPlugin;
+pub use user::UserMetaPlugin;
+pub use shell::ShellMetaPlugin;
+pub use shell_pid::ShellPidMetaPlugin;
+pub use keep_pid::KeepPidMetaPlugin;
+pub use hostname::HostnameMetaPlugin;