Do a large chunk of the move to go

This commit moves a huge chunk of the code to go. The TODO.md document
indicates what is left to be done.

distillery/resources/runtime/utils/wisski_2x_3x.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+set -e
+
+# temporarily extend permissions
+chmod 777 web/sites/default
+chmod 666 web/sites/default/*settings.php
+chmod 666 web/sites/default/*services.yml
+
+# update the core itself
+composer require 'drupal/core-recommended:^9' 'drupal/core-composer-scaffold:^9' 'drupal/core-project-message:^9' --update-with-dependencies --no-update
+composer update
+composer require 'drupal/wisski'
+
+# update requirements for wisski!
+pushd web/modules/contrib/wisski || exit 1
+composer update
+popd || exit 1
+
+# run the update and clear the cache!
+drush updatedb --yes
+# drush cc
+
+# and reset everything back to normal
+chmod 755 web/sites/default
+chmod 644 web/sites/default/*settings.php
+chmod 644 web/sites/default/*services.yml