Modding while limited at the moment, has got quite a community behind it and is in fact available for all releases of the game, not just on itch.io. You'll find it over at the official Dicey Dungeons discord https://discord.gg/PBW2t76
As for learning how to mod, there are no real guides for it at the moment, you'll find in your Dicey Dungeons/date/MODDING.txt file the basics of it but that's it. However the people (me included) over at the discord will gladly help you and answer your questions.
As for how to really learn, the best way currently, is looking at how the files in the base game are organized, and also taking a look at how other mods are made. If you want to take a look at user created mods, the best place for that at the moment is on itch.io https://itch.io/game-mods/tag-dicey-dungeons
The Api is a bit limited at the moment, but you could already mod in : Equipment, Enemies, Bonus Round Remixes, Episodes (as replacement to already existing ones), Very limited characters (as replacement to already existing ones), New floor layouts, you can change the floor generation, More Gadgets, and somehow new status effects(but it's kind of hacky), and probably a bit more. If you want to check already released mods, most are available here : https://itch.io/game-mods/tag-dicey-dungeons If you need some help with modding, The Dicey Dungeons Discord is a good place for that.
If it's something that is really irritating you, make yourself a mod! What your asking for is pretty easy.
Check out Dicey Modgeons to download the official modding tool and check out the official Dicey Dungeons modding channel on discord. There's a community of really helpful people there that would be more than happy to help if you ask nicely.
Either that or you could do a find and replace of the offending phrases in the csv files in the Dicey Dungeon data/text directory and get most if not all of them.