Enable all options in example.drush.yml and make `sql:dump` work

[gitressa]

examples/example.drush.yml

Wouldn't it be better to streamline options in https://github.com/drush-ops/drush/blob/13.x/examples/example.drush.yml and make them all active? Supposedly, the user knows that commenting out an option is possible.

Also, the sql:dump > structure-tables-key: common example doesn't work without defining the actual tables under sql ("Non-options") so maybe include them as well?

docs/using-drush-configuration.md

We could also add the user:login example on https://www.drush.org/13.x/using-drush-configuration

• https://github.com/drush-ops/drush/blob/13.x/docs/using-drush-configuration.md