feat: add a comment with the repo’s release version or latest commit to the manuscript

[ycexiao]

Problem

In #12 and #14, we want to let scikit-package-manuscript fetch the LaTeX headers and insert them in the manuscript. Since the contents of a repo can change, we also need to comment on the version number or the latest commit of the headers

Proposed solution

Use request and the GitHub API to fetch the release version and the latest commit.