Not a good idea IMO in a manual. You'd have to somehow override the "clutch must be depressed" feature, and then you'd run into problems if you ever left it in gear. Your truck would run into things, and worst case, into people.
I think it's even difficult to find somebody to have it installed, as most shops will not want to take the risk.
The only responsible way to do this would be to implement some switch / circuit that requires the transmission to be in neutral for the truck to be started. Not sure if that exists, but I have never heard of it. And even with that, I sure would not rely on some homemade patch.
Bottom line --- this could become a very expensive add on --- either way. Probably not worth it.
BTW, what do you need it for? Have the truck pick you up at the front door of the supermarket? (just kidding)
