with open("app/modules/sag/templates/detail.html", "r") as f:
    content = f.read()

target = '<button class="btn btn-sm btn-link text-muted p-0 mb-1" onclick="startTitelEdit()" title="Rediger overskrift"><i class="bi bi-pencil-square"></i></button>'
replacement = target + '\n                                <button class="btn btn-sm btn-link text-info p-0 mb-1 ms-2" onclick="openManualHelp(\'Sag\')" title="Hjælp til sagsbehandling"><i class="bi bi-question-circle fs-5"></i></button>'

content = content.replace(target, replacement)

with open("app/modules/sag/templates/detail.html", "w") as f:
    f.write(content)