wrap refresh logic in vim.schedule callback

lua/lib/lib.lua

@@ -118,6 +118,8 @@ local function refresh_nodes(node)
 end
 
 function M.refresh_tree()
+  vim.schedule(
+    function ()
       -- local stat = luv.fs_stat(M.Tree.cwd)
       -- if stat.mtime.sec ~= M.Tree.last_modified then
       refresh_nodes(M.Tree)
@@ -131,6 +133,7 @@ function M.refresh_tree()
       else
         M.Tree.loaded = false
       end
+    end)
 end
 
 function M.set_index_and_redraw(fname)