should
- close #85
 
## description
### before
```
pkgs/nu-git-manager/
|-- nu-git-manager
|   |-- completions
|   |   `-- nu-complete.nu
|   |-- error
|   |   `-- error.nu
|   |-- fs
|   |   |-- cache.nu
|   |   |-- dir.nu
|   |   |-- path.nu
|   |   `-- store.nu
|   |-- git
|   |   |-- repo.nu
|   |   `-- url.nu
|   `-- mod.nu
|-- nupm.nuon
`-- tests
    |-- gm.nu
    `-- mod.nu
```
```
pkgs/nu-git-manager-sugar/
|-- nu-git-manager-sugar
|   |-- completions
|   |   `-- nu-complete.nu
|   |-- extra.nu
|   |-- git
|   |   |-- lib
|   |   |   |-- lib.nu
|   |   |   |-- prompt.nu
|   |   |   `-- style.nu
|   |   |-- mod.nu
|   |   `-- prompt.nu
|   |-- github.nu
|   `-- mod.nu
|-- nupm.nuon
`-- tests
    |-- git.nu
    `-- mod.nu
```

### after
> **Important**
>  caveats:
> - `[1]`: has `use path.nu ...` instead of `use path`
> - `[2]`: has `use style.nu ...` instead of `use style`

```
pkgs/nu-git-manager/
|-- nu-git-manager
|   |-- completions.nu    # internal
|   |-- error.nu          # internal
|   |-- fs                # internal
|   |   |-- cache.nu   [1]
|   |   |-- dir.nu     [1]
|   |   |-- mod.nu
|   |   |-- path.nu
|   |   `-- store.nu   [1]
|   |-- git               # internal
|   |   |-- mod.nu
|   |   |-- repo.nu
|   |   `-- url.nu
|   `-- mod.nu
|-- nupm.nuon
`-- tests
    |-- gm.nu
    `-- mod.nu
```
```
pkgs/nu-git-manager-sugar/
|-- nu-git-manager-sugar
|   |-- completions.nu        # internal
|   |-- extra.nu              # public
|   |-- git                   # public
|   |   |-- lib               #     internal
|   |   |   |-- git.nu     [2]#         public
|   |   |   |-- mod.nu
|   |   |   |-- prompt.nu     #         public
|   |   |   `-- style.nu   [2]#         public
|   |   |-- mod.nu
|   |   `-- prompt.nu         #     public
|   |-- github.nu             # public
|   `-- mod.nu
|-- nupm.nuon
`-- tests
    |-- git.nu
    `-- mod.nu
```

## TODO
- [x] `nu-git-manager-sugar/git/lib` issue with `prompt.nu` in
77596ff