add package doc comments

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

acl/export.go

@@ -1,3 +1,4 @@
+// Package acl implements simple ACL manipulation via libacl.
 package acl
 
 import "unsafe"

dbus/dbus.go

@@ -1,3 +1,4 @@
+// Package dbus wraps xdg-dbus-proxy and implements configuration and sandboxing of the underlying helper process.
 package dbus
 
 import (

helper/helper.go

@@ -1,6 +1,4 @@
-/*
-Package helper runs external helpers and manages their status and args FDs.
-*/
+// Package helper runs external helpers with optional sandboxing and manages their status/args pipes.
 package helper
 
 import (

ldd/ldd.go

@@ -1,3 +1,4 @@
+// Package ldd retrieves linker information by invoking ldd from glibc or musl and parsing its output.
 package ldd
 
 import (

xcb/export.go

@@ -1,3 +1,4 @@
+// Package xcb implements X11 ChangeHosts via libxcb.
 package xcb
 
 //#include <stdlib.h>