git switch should require -d or --detach for detached HEAD

[smurfton]

As I said in the title. You currently don't accept -d or --detach, but git switch rejects anything that results in a detached HEAD unless -d or --detach is passed

[pcottle]

Oh interesting, yeah I made this whole course before git switch was popular so not surprised I missed something. Probably not a huge burning issue but will leave this open