huge reordering of config

add codeium plugin
change keymaps for completion picker to up/down/tab
remove comments
compact config

lua/plugins/codeium.lua

@@ -0,0 +1,17 @@
+--
+-- Codeium
+-- https://github.com/Exafunction/codeium.nvim
+--
+
+return {
+
+  'Exafunction/codeium.nvim',
+  dependencies = {
+    'nvim-lua/plenary.nvim',
+    'hrsh7th/nvim-cmp',
+  },
+  event = 'BufEnter',
+  config = function()
+    require('codeium').setup {}
+  end,
+}