Proposed commit log message:
```
[NEW PORT] sysutils/py-cron-descriptor: Converts cron expressions into human readable strings
A Python library that converts cron expressions into human
readable strings. Ported to Python from
https://github.com/bradyholt/cron-expression-descriptor.
WWW: https://github.com/Salamek/cron-descriptor
Reviewed_by: koobs
Approved by: koobs (mentor)
Differential_Revision:
```