There is a reference to the `sites/default/files` in the database so that structure is mandatory for the migration.
The path in the `upgrade_d7_file.yml` migration file is different because this is executed inside the docker container so in the
docker container the <ProjectRoot> is: `/var/www/html/` but no need to re-create those folders in the host machine.
Create a database called `drupal7` with the content of the old site, [check here how to create the database](https://stackoverflow.com/a/49785024/1943924)
Once the files are in the correct place and the database has been created we can run the following to run all the migrations: