Add the documentation and guide node migrations.
Closes #3474989
to test:
- update the config for the drupalorg_migrate module
- run the file migrations ether individually or by using the
files
group in the migration script - run the documentation node migration
ddev drush mim drupalorg_migrate_documentation
- run the guide node migration
ddev drush mim drupalorg_migrate_guide
- all of the documentation and guide nodes should be migrated with all of the appropriate entity reference fields populated
ToDo: the related content field will need to be updated once the Page and Change Notice migrations have been added.