[Feature Request] Import data from mastodon instance

I'm currently hosting my own mastodon instance. I want to migrate to wildebeest but keep my username & followers unchanged.
Two possible options:
1. import toots and RSA keys from mastodon database
2. import toots from mastodon database. Provide a way to send Update activity to all my followers with the old key. (For example, I call a API with my old private key, and wildebeest send the Update activity to all my followers)