FIX: added back 'ordinal'; appears to be mandatory

Appears to be required for Telescope to display the snippets list at
all.  See the Telescope developer's documentation here:

<https://github.com/nvim-telescope/telescope.nvim/blob/master/developers.md#entry-maker>

lua/telescope/_extensions/luasnip.lua

@@ -130,6 +130,7 @@ M.luasnip_fn = function(opts)
                     filename = entry.context.trigger,
                     display = make_display,
                     text = string.format(" => %s | %s | %s", entry.ft, entry.context.name, entry.context.description[1] or ''),
+                    ordinal = search_fn(entry),
                     preview_command = function(_, bufnr)
                         local snippet = get_docstring(luasnip, entry.ft, entry.context)
                         if opts.preview.check_mime_type then