Merge 'upstream': various fixes

- Propsed fix for init.lua warnings
- Remove duplicate cmp-path
- fix: regression introduced in db78c0b217
- Fix: fix the cmp-nvim-lsp-signature-help link
- feat: add basic function signature help
- perf: load tokyonight.nvim in the intended way

lua/kickstart/plugins/cmp.lua

@@ -34,6 +34,7 @@ return {
       --  into multiple repos for maintenance purposes.
       'hrsh7th/cmp-nvim-lsp',
       'hrsh7th/cmp-path',
+      'hrsh7th/cmp-nvim-lsp-signature-help',
     },
     config = function()
       -- See `:help cmp`
@@ -110,6 +111,7 @@ return {
           { name = 'nvim_lsp' },
           { name = 'luasnip' },
           { name = 'path' },
+          { name = 'nvim_lsp_signature_help' },
         },
       }
     end,