protect the calls to `require` with `pcall`

This is to make sure `nvim` can start even if the files are not
defined by the user.

init.lua

@@ -230,7 +230,7 @@ vim.o.completeopt = 'menuone,noselect'
 -- NOTE: You should make sure your terminal supports this
 vim.o.termguicolors = true
 
-require('custom/options')
+pcall(require, 'custom/options')
 
 -- [[ Basic Keymaps ]]
 
@@ -242,7 +242,7 @@ vim.keymap.set({ 'n', 'v' }, '<Space>', '<Nop>', { silent = true })
 vim.keymap.set('n', 'k', "v:count == 0 ? 'gk' : 'k'", { expr = true, silent = true })
 vim.keymap.set('n', 'j', "v:count == 0 ? 'gj' : 'j'", { expr = true, silent = true })
 
-require('custom/keybindings')
+pcall(require, 'custom/keybindings')
 
 -- [[ Highlight on yank ]]
 -- See `:help vim.highlight.on_yank()`
@@ -500,4 +500,4 @@ cmp.setup {
 -- The line beneath this is called `modeline`. See `:help modeline`
 -- vim: ts=2 sts=2 sw=2 et
 
-require('custom/commands')
+pcall(require, 'custom/commands')