Use Ctrl-/ for commenting (may change later)

Currently considering whether to use this VSCode-style keykind or
whether to switch to the more Vimic "gc" family of commands; I am
somewhat finding the Ctrl-/ method to be more familiar, but less
efficient given the layout of my fingers in Neovim.

lua/plugins/comments.lua

@@ -4,12 +4,17 @@ return {
         "numToStr/Comment.nvim",
         opts = {
             -- add any options here
+            toggler = {
+                line = "<C-_>",
+            },
+            opleader = {
+                line = "<C-_>",
+            },
         },
         lazy = false,
     },
     {
         "folke/todo-comments.nvim",
         dependencies = { "nvim-lua/plenary.nvim" },
-        opts = {},
     },
 }