Ideas for package refresh

Since we're starting to maintain this again (for use in CompatHelper and eventually TagBot too), there are a couple of things that I would like:

- [x] - Solve #12; I really dislike the `Response{T}` design pattern that I used (https://github.com/JuliaWeb/GitForge.jl/commit/c6bbc7b4029459eca9eed61ac540ec9ae7a41dac does this but I never got it into master for whatever reason)
- [ ] - Clean up pagination: I think it would be nice if pagination were handled more automatically, e.g. instead of explicitly calling `@paginate`, we return a lazy paginator by default. The logic of the pagination itself can probably be cleaned up too. (#18, #17)
- [ ] - Move from JSON2 to JSON3 (JSON2 is unmaintained AFAIK)
- [ ] - Tests: [BrokenRecord](https://github.com/JuliaTesting/BrokenRecord.jl) is a good fit for testing this package.
- [ ] - Refactor endpoint definition API? I quite like what I did with [Discord.jl](https://github.com/christopher-dG/Discord.jl/blob/d34d16374fd668c167ec8bf57581767a537f8b27/src/routes.jl#L205-L227), but this isn't really necessary and would be strictly internal so it could happen at any time. The implementation is also super messy so maybe it ought to be factored out into an external package.