refactor: clarify bookmark variable naming

Author: xiantang

lua/nvim-tree/explorer/filters.lua

@@ -133,23 +133,24 @@ function Filters:bookmark(path, path_type, bookmarks)
   end
 
   local mark_parent = utils.path_add_trailing(path)
-  for mark, mark_type in pairs(bookmarks) do
-    if type(mark_type) == "table" and mark_type.type then
-      mark_type = mark_type.type
+  for bookmark_path, bookmark_entry in pairs(bookmarks) do
+    local bookmark_type = bookmark_entry
+    if type(bookmark_entry) == "table" and bookmark_entry.type then
+      bookmark_type = bookmark_entry.type
     end
-    if path == mark then
+    if path == bookmark_path then
       return false
     end
 
     if path_type == "directory" then
       -- check if path is mark's parent
-      if vim.fn.stridx(mark, mark_parent) == 0 then
+      if vim.fn.stridx(bookmark_path, mark_parent) == 0 then
         return false
       end
     end
-    if mark_type == "directory" then
+    if bookmark_type == "directory" then
       -- check if mark is path's parent
-      local path_parent = utils.path_add_trailing(mark)
+      local path_parent = utils.path_add_trailing(bookmark_path)
       if vim.fn.stridx(path, path_parent) == 0 then
         return false
       end