Feature request: an option to raise/lower he flag

[seanpm2001]

I came up with this idea last night, and I think it would be a good addition to the program.
There should be a scroll-able option that lets you lower and raise the flag.

[Bluellama2022]

Half mast is also a good idea as it helps pay respect. However, this cannot work with vertically displayed flags (e.g. on a crossbar) as they should have black crêpe streamers.