feat: add pagination support

[maciek134]

Added pagination support, resolves #68 (and more, since it's supported in all feed types).

[coveralls]

Coverage increased (+3.4%) to 99.029% when pulling 1009a97 on maciek134:feat/pagination into c4666db on jpmonette:master.

[maciek134]

@jpmonette actually if you want I could add proper pagination support - so the library would paginate automatically and you could get specific pages using a method like .getPage(n: number)

[jpmonette]

@maciek134 I'm not sure how this would be maintainable in the current state - seems like a lot of maintenance for a developer to add pagination - the developer would have to create many instances of Feed and manually set next / prev, no?

Please, open an issue instead with what you want to achieve and suggested designs decisions as I'm not sure this is the best approach. I'm sure this could be valuable for the library, but in a different shape.

Thanks for the time spent here.

[vedmant]

So this was rejected? Pity, only because it has no pagination I can't use this library

[maciek134]

So this was rejected? Pity, only because it has no pagination I can't use this library

And with good reasoning. I missed the reply though, otherwise I would have tried to fix the PR. I had an idea for a proper solution back then (that doesn't require so much manual work) but I needed this quickly and just shared my "fix". I'll try to revisit when I have time.