This is a v3 prerelease, so handle with care and expect everything/anything to still change. Adding this as a dependency with a non-exact range like ^3.0.0-2 will almost certainly eventually break your build when new prereleases are made available. This version has been published to npm using the next dist-tag, so install it with:
npm install --save-exact yaml@next
I don't have a clear idea how close or far this is from the eventual v3 final release; see its milestone for a very rough and incomplete idea of what's on the table so far.
By far the biggest change in this release is #699, a collection of performance improvements by @43081j. It should not have any user-visible API changes, except for many things now being a bit faster.