Outdated - go get your hands on v0.1.1 which is a full install anyway.
(the reason for the small size is that the download is entirely text files in one format or another).
To install - either open Comments.txt or follow these three easy steps:
The mod supports campaigns fine, if rather oddly (e.g. you won't be able to train Dwarven Workers in Good Dwarven Campaigns due to them being Tier III, but in the first campaign you can solo with Gimli and Boromir (because bugginess) and in the second the Ancient Catapult insta-builds anyway.
For proper campaign support see the other download, which is much much larger (even then, still only 120 MB or so) that I haven't actually put up yet & will get around to fairly soon. This is not extensive campaign editing - it's basically just support. It also usually buffs the AI because aside from the last campaign it's incredibly easy.