cli command for formatting

**Is your feature request related to a problem? Please describe.**
It would be good if we could have access to this simple formatting from the command line.

**Describe the solution you'd like**
```
$ paragraphical -f file.txt
....
$ cat file.txt | paragraphical
...
```

**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.

**Additional context**
Add any other context or screenshots about the feature request here.