Page loading should load resources

When navigating form repositories list to a repository currently we do not load issues and milestones.

Look at the navigation code for the repository list and the repository detail view. Identify where issues and milestones are fetched. The fix likely involves ensuring these resources are loaded on page transition. Check the Elm architecture's update function and HTTP commands. Verify by navigating and confirming the data loads.

索引モデルが issue の本文から書いたものです。