Add ability to add a label when creating a new bug

[harleypig]

It would be really useful to have the option to add labels directly when creating a bug, particularly when I'm importing a bunch of tasks or projects manually from a todo list.

Also, when I'm in the middle of something and notice an issue that needs fixing but I'm not able to address it immediately, remembering to go back and add a label can be a bit disruptive to my workflow.

Adding a --label switch to the add command, and maybe a #Label: prefix in the file format for the -F switch would be helpful.

[harleypig]

I tossed together a bash script to do this. It's rough ... I just used chatgpt and massaged it a little. I can't do this everywhere I use git bug, so it's not a global solution.