Add a option to create multiple releases in one combined Github release

[bdbch]

Hey! Over at Tiptap we use Changesets to manage our release and versioning process - however one thing we miss is controlling how the action is creating Github releases.

We use fixed versioning in our monorepo as our packages usually are dependent on each other or at least the core and util packages so we want to make it easier for our users to figure out what packages are compatible with each other.

Now if we create Github releases with our normal releases, we run into the issue of absolutely spamming our followers home screens with releases of all our 15+ packages everytime we do a minor/patch bump haha.

I'd like to have a bit more control and instead of creating a release per-package have one global release changelog.

That way users using fixed versioning can create a github release for their one version instead of per package.