Add npc generation command

[DawidIzydor]

We all have been in a situation where a player gets to a tavern and start asking stupid questions like "what's the name of the bar maiden". To avoid having the exact same NPC all the time use /gpt npc command instead

I have this ready to go and will create a PR shortly

[DawidIzydor]

Created #29, example usage

[Grandsome]

Great script, I edited my files to test it, I wonder if there could be some formatting to make the gpt answers easier to read, also implemented the breakline PR in my files to help. The role-playing hints part is hit or miss, maybe that prompt could be optimized, or maybe it's just a translation issue (gpt has been weird with translation lately). Also, gpt does take while to generate the answer, I don't know if that can be helped.