Align the task descriptions.

This PR changes the output of the help command from

```
[gulp] Starting 'help'...

Usage:
  gulp [task]

Available tasks:
  help Display this help text
  init Initializes the project.
  migrate Run pending migrations.
  migrate:undo Undo the last migration.
  migration:create Creates a new migration.
  version Prints the version number.

[gulp] Finished 'help' after 3.19 ms
```

to

```
[gulp] Starting 'help'...

Usage:
  gulp [task]

Available tasks:
  help              Display this help text
  init              Initializes the project.
  migrate           Run pending migrations.
  migrate:undo      Undo the last migration.
  migration:create  Creates a new migration.
  version           Prints the version number.

[gulp] Finished 'help' after 1.93 ms
```