add shop documentation and fix shop remove

internal/shop.cm

@@ -1313,6 +1313,20 @@ Shop.remove = function(pkg) {
     Shop.save_lock(lock)
   }
 
+  // Remove package symlink/directory
+  var pkg_dir = get_packages_dir() + '/' + safe_package_path(pkg)
+  if (fd.is_link(pkg_dir)) {
+    fd.unlink(pkg_dir)
+  } else if (fd.is_dir(pkg_dir)) {
+    fd.rmdir(pkg_dir, 1)
+  }
+
+  // Remove built dylibs
+  var lib_dir = global_shop_path + '/lib/' + safe_package_path(pkg)
+  if (fd.is_dir(lib_dir)) {
+    fd.rmdir(lib_dir, 1)
+  }
+
   log.console("Removed " + pkg)
   return true
 }