[nvim] Convert init.vim to init.lua and copy over a bit of the vimrc config to some lua scripts

This is neat!

config/nvim/lua/keys.lua

@@ -0,0 +1,22 @@
+-- Eryn Wells <eryn@erynwells.me>
+
+local map = vim.keymap.set
+
+vim.g.mapleader = ","
+
+local options = { silent = true }
+
+-- Allow starting commands with ; instead of typing Shift-;. Save lots of keypresses!
+map('n', ';', ':')
+
+map('n', '<C-h>', '<C-w>h', options)
+map('n', '<C-j>', '<C-w>j', options)
+map('n', '<C-k>', '<C-w>k', options)
+map('n', '<C-l>', '<C-w>l', options)
+
+map('n', '<C-n>', ':bn<CR>', options)
+map('n', '<C-p>', ':bp<CR>', options)
+
+map('n', '<leader><space>', function()
+    vim.exec [[ setlocal invhlsearch ]]
+end, options)