Function walk_tree_dir 

fn walk_tree_dir(
    repo_path: &Path,
    repo: &Repository,
    tree_id: ObjectId,
    dir_path: &str,
    commit_hash: &str,
    rev_dir: &Path,
    tera: &Tera,
    project_name: &str,
    lang: &Option<String>,
    clone_url: &Option<String>,
    ss: &SyntaxSet,
    theme: &Theme,
) -> Result<()>

Recursively generate one index.html (directory listing) per tree and one <name>.html per blob, rooted at rev_dir. TODO: Fix clippy warning about too many arguments