Update `prer` to use commit messages and or PR content so release notes can be generated

### Description of the problem / feature request:
Previously we were able to construct release notes by hovering over the commit hashes but GitHub has removed showing previews of the PRs linked to the commits.

The commit history on the PR branch can no longer be used to crate release notes easily

### Feature requests: what underlying problem are you trying to solve with this feature?
prer should automate or make it easy to view all the commit messages that resulted in the manifest changes. E.g. automate the release notes.

### Have you found anything relevant by searching the web?

Automating release notes via commit messages: https://www.conventionalcommits.org/en/v1.0.0/

L’issue mentionne `prer`, mais aucun fichier ni test. Commencez par localiser le code qui gère les modifications du manifeste et la sortie de release, puis déterminez comment les messages de commit ou le contenu de la pull request sont disponibles ; le travail est terminé lorsque `prer` peut afficher ou générer des release notes pour les commits à l’origine des modifications du manifeste.

Rédigé par le modèle d'indexation à partir du texte de l'issue.