Improve and update Drush documentation

[platformsh]

Improve and update Drush documentation

[Barry-Fisher]

Bump on this. I had to submit a support request after getting errors with running sql-sync.

I've sorted our issue by adding a mount point for drush-backups.

Any chance of merging this PR in soon for pjcdawkins/platformsh-examples@950f7cd?

[Crell]

The D7 starter kit has the drush-backups mount defined now:
https://github.com/platformsh/platformsh-example-drupal7/blob/master/.platform.app.yaml

Do we need the same on Drupal 8 as well? That's an easy enough PR for the D8 example if so.

[Barry-Fisher]

Hi Crell. That's right we need the drush-backups mount point in the D8 version of the docs too.

I've created a PR on the platformsh-example-drupal8 repo: https://github.com/platformsh/platformsh-example-drupal8/pull/4

[Crell]

Thanks, PR has been merged.