My first try at contributing something.
From what I see I have to make a pull request besides the commit, how do I do that?
Nevermind, got it!
Scratch that. The pull request page says it failed. What did I do wrong? I can’t figure it out by the failure details report.
It seems to be something on the professions file specifically but I can’t figure out what. Was the separation from the previous profession badly done? The change seems to be encompassing the }, from the previous one.
And I’m not sure how to go about adding them to the itemgroups file. Should I add them to existing categories or make a new category, like cops? Maybe one could later on implement a postal office and have postal office cloth spawn on zombies and in said offices. Some tips?
I went ahead and merged it. I think the error it reported was a merge issue, the json files frequently have this problem. The best way to avoid it is to pick a random or category-based spot to stick your new content instead of at the end (for example put the mail carrier after the cop). This makes it less likely that two different people edit the same spot in the file, which is what causes conflicts.
In addition to that, there were some commas missing in the profession definition, but I just fixed that up in the merge.
It’s ok to have items only spawn with a profession, but if you think of somewhere else that it would make sense for those items to appear, by all means add them.
Thanks for the contribution 
I will give a look over the itemgroups later to see where it would make sense.
And you’re very welcome, happy to be able to give something back to the community.
Would these work to make these appear together on zombies so as to simulate zombie mail carriers?