Resurrect the "doodle poll" to make sure that there is cover during working hours

[JackiePease]

@amcewen mentioned that there used to be a weekly Doodle poll allowing organisers to say when they were going to be in the space. An email was then sent out if any time wasn't covered to make sure there was someone there to open the door etc.

This seems like a good idea to resurrect if there is something similar around these days.

[amcewen]

We've used a spreadsheet to fulfil this role over the summer, when fewer of us have been in. Maybe we can extend it to run indefinitely? Would be good to have some support for automating reminders to fill it in and reminders the day before a day that still has a gap in cover.