Support more than one project

[christianliebel]

This PR adds support for more than one project in the projects array, concatenated into a single string.

[christianliebel]

@microsoft-github-policy-service agree

[tomayac]

LGTM, thanks

[jakebailey]

Since this touches a published package, it'll need a changeset. You can just do pnpm changeset and say it's a patch release.

That being said, this technically sticks display formatting into the parser. I think it would probably make more sense to leave projectName, add a new projects getter that returns the whole array, then use that in the code that produces the readme.