R1:19b2eb57a94d

Improve lipsum generation of projects

Summary:
Fixes T9156.

- Fix hashtag generation.
- Fix various badnesses.
- Improve project name generator.

Test Plan:
```
$ ./bin/lipsum generate projects
GENERATORS Selected generators: Projects.
WARNING This command generates synthetic test data, including user accounts. It is intended for use in development environments so you can test features more easily. There is no easy way to delete this data or undo the effects of this command. If you run it in a…