Add neovim config with kickstart-modular. Update shell configs.

config/nvim/lua/kickstart/plugins/indent_line.lua

@@ -0,0 +1,9 @@
+return {
+  { -- Add indentation guides even on blank lines
+    'lukas-reineke/indent-blankline.nvim',
+    -- Enable `lukas-reineke/indent-blankline.nvim`
+    -- See `:help ibl`
+    main = 'ibl',
+    opts = {},
+  },
+}