Add formatting.deprecated option

lua/cmp/config/default.lua

@@ -51,6 +51,7 @@ return function()
     mapping = {},
 
     formatting = {
+      deprecated = true,
       format = function(_, vim_item)
         return vim_item
       end

lua/cmp/entry.lua

@@ -204,8 +204,10 @@ entry.get_vim_item = function(self, suggest_offset)
     end
 
     -- deprecated
-    if completion_item.deprecated or vim.tbl_contains(completion_item.tags or {}, types.lsp.CompletionItemTag.Deprecated) then
-      abbr = str.strikethrough(abbr)
+    if config.get().formatting.deprecated then
+      if completion_item.deprecated or vim.tbl_contains(completion_item.tags or {}, types.lsp.CompletionItemTag.Deprecated) then
+        abbr = str.strikethrough(abbr)
+      end
     end
 
     -- append delta text

lua/cmp/types/cmp.lua

@@ -75,6 +75,7 @@ cmp.ScrollDirection.Down = 'down'
 ---@field public comparators function[]
 
 ---@class cmp.FormattingConfig
+---@field public deprecated boolean
 ---@field public format fun(entry: cmp.Entry, vim_item: vim.CompletedItem): vim.CompletedItem
 
 ---@class cmp.SnippetConfig