Currently there aren't any achievements specifically for peaceful playthroughs but you can get a few without much fighting if you're clever about it. The loophole achievement comes from talking your way through wyll's pact situation, and leave no one bbehind focuses mainly on helping the tiefling refugees through various acts which mostly needs good choices rather than combat. There's also rude crude and full of attitude, where you'll just need to find and summon shovel through exploration

Most of the hidden stuff actually tracks big story moments, special combat encounters, or specific dark urge choices but some like under lock and key let you mix diplomacy and stealth to rescue prisoners. While there's no pure pacifist achievements right now, the game really does reward creative problem-solving, and you'll find lots of non-violent solutions even if they don't pop a trophy. Tip - save before important conversations since dialogue choices can sometimes lead to unexpected fights you might want to avoid

If you're going for minimal combat maybe interesting to know that some seemingly violent achievements can actually be done pretty peacefully if you're patient with dialogue options and use good timing with stealth