v0.5.0

Five new tools for reading the plan over time: get_runway says how many months the money set aside would last (#91); get_savings_rate says how much of the income was kept, month by month (#92); get_underfunded_targets says which targets still need money this month (#93); get_debt_payoff_plan says when the debts would be paid off, avalanche or snowball (#94); get_age_of_money shows YNAB's Age of Money month by month, and its trend (#95).

Also: the site and the repository show a card when shared (#96). No breaking change. See CHANGELOG.md.