Add more plugins mainly from LazyVim

lua/custom/plugins/lsp-signature.lua

@@ -2,9 +2,10 @@
 return {
   'ray-x/lsp_signature.nvim',
   event = 'VeryLazy',
-  opts = {},
+  opts = {
+    toggle_key = '<C-g>',
+  },
   config = function(_, opts)
     require('lsp_signature').setup(opts)
-    vim.keymap.set('i', '<C-g>', vim.lsp.buf.signature_help, { silent = true, noremap = true, desc = 'toggle function signature' })
   end,
 }