R1:ba37149bf97b

Improve bin/lipsum UX

Summary: Ref T9156. This makes the UX a little more modern/standard/safe.

Test Plan:
```
epriestley@orbital ~/dev/phabricator $ ./bin/lipsum generate
Choose which type or types of test data you want to generate, or select "all".

- Differential Revisions
- Files
- Maniphest Tasks
- Pastes
- Pholio Mocks
- Projects
- User Accounts
```

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9156

Differential Revision: https://secure.