📑 Generate PDF exports of promo's timesheet

Asked by @LudovicPatho - they need to generate pdf exports of timesheets for the FOREM.

The new underlying structure of graph/mybecode makes the operation quite complex to perform _online_ (configuring lambda to generate pdf), while, with the cli, we can get the data (after the #24 refactor), generate local html pages, then export to pdf, using the hardware of the user.

### Command Process

> ⚠ only for _coaches_ and _EMO_

- Select promo
- Select date range (start and end)
- Generate html pages
- Export to pdf (two npm packages seems useful: [pdfmake](https://www.npmjs.com/package/pdfmake) & [pdfkit](https://www.npmjs.com/package/pdfkit))