Move long commands from dotbot config into scripts

Move long commands from the dotbot config into own scripts to keep the
install.conf.yaml more readable.
Fix bug that the submodule init step fails when already done once since
then the grep statement fails because there is no output.

meta/archive

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+tmpd="$(mktemp -d)"
+
+for file in .config/*; do
+	[ ! -e "$HOME/$file" ] || mv "$HOME/$file" "$tmpd"
+done
+
+if rmdir "$tmpd" 2>/dev/null; then
+	echo "Nothing to archive"
+else
+	name="existing-$(date +"%s").tar.gz"
+	if tar czvf "$name" "$tmpd"; then
+		rm -rf "$tmpd"
+		echo "$name created"
+	else
+		echo "Archive could not be created. See $tmpd."
+		exit 1
+	fi
+fi