Schedule volunteer roles

[github-actions[bot]]

We need to work out how many people we need doing each role and then come up with a timetable which shows who is doing which role when.

A noted job that should be remembered is delivering refreshments to volunteers that have long shifts and cannot leave their posts for long periods of time.

Required actions:

• [ ] Capture volunteer job preferences
• [ ] Schedule roles

Original

comp/volunteers/schedule

### Dependencies
 - [ ] #1412

[sedders123]

Make sure someone is on reception for entire time building is open https://github.com/srobo/tasks/issues/1177

[sedders123]

Ensure we have flexibility of shift timings https://github.com/srobo/tasks/issues/1172