home: vim: use actual lua files

Since most of the settings are actually just lua in a VimL file.

home/vim/plugin/numbertoggle.lua

@@ -0,0 +1,23 @@
+-- Show lines numbers
+vim.opt.number = true
+
+local numbertoggle = vim.api.nvim_create_augroup("numbertoggle", { clear = true })
+
+-- Toggle numbers between relative and absolute when changing buffers
+vim.api.nvim_create_autocmd({ "BufEnter", "FocusGained", "InsertLeave", "WinEnter" }, {
+    pattern = "*",
+    group = numbertoggle,
+    command = "if &nu | setlocal rnu | endif",
+})
+vim.api.nvim_create_autocmd({ "BufLeave", "FocusLost", "InsertEnter", "WinLeave" }, {
+    pattern = "*",
+    group = numbertoggle,
+    command = "if &nu | setlocal nornu | endif",
+})
+
+-- Never show the sign column in a terminal buffer
+vim.api.nvim_create_autocmd({ "TermOpen" }, {
+    pattern = "*",
+    group = numbertoggle,
+    command = "setlocal nonu nornu",
+})