feat(extmark): window scoped extmark

Co-authored-by: zeertzjq <zeertzjq@outlook.com>

runtime/lua/vim/_meta/api_keysets.lua

@@ -252,6 +252,7 @@ error('Cannot require a meta file')
 --- @field ui_watched? boolean
 --- @field undo_restore? boolean
 --- @field url? string
+--- @field scoped? boolean
 --- @field _subpriority? integer
 
 --- @class vim.api.keyset.user_command