Constant PROJECT_PLACE 

pub const PROJECT_PLACE: &str = "\
Put a project inside a portfolio, or take it out.

```
ytcli project place 655… --into 644…
ytcli project place 655… --out
```

Same shape as `portfolio place`, and the same version check.

A project belongs to one portfolio at a time. Putting it in another moves it;
nothing is duplicated, and nothing else about the project changes.";