I have used Excel to make tags from a table before. Usually just for one off stuff and before I was very familiar with JavaScript.
E.g. if you have a table of 100 urls you could use excel to easily turn them into a
tags using the various text formulas like concat.
It’s probably never the best tool for the job but sometimes I’ll do stuff in Excel just because I’m very familiar with it.
To clarify I am not a programmer by trade lol
Apparently official skin support no longer exists but Millennium for Steam looks like an unofficial tool that can be used for skins.