feature: successful post to Mastodon notification

please consider adding a message to indicate that Mastodon received the post

i believe WP has an API for this that prints messages at the top of the post page, however also please have a look at the way Jan did it with his plugin

also i’m noticing longer delays when publishing and i assume this is due to the Mastodon instance – the concern her is that one doesn’t know what’s happening; was the WP post successful and we’re just waiting on Mastodon? and what happens if posting to Mastodon fails (times out) – does the WP post fail also? if there’s a way to indicate status that would be nice