Writing documentation was good for #GoActivityPub.
It gives me the opportunity to go through some user scenarios for the tools I'm documenting and make sure that they work the way I'm describing.
I've fixed a couple of issues in this way these past days.
https://man.sr.ht/~mariusor/go-activitypub/go-ap/pitfalls.md#changing-the-type-of-an-object