fix nextpage logic and add additionalParameters logic and example

[tnrich]

Let me know if you have questions. This fixed the issue I was seeing - #21

[codecov]

Codecov Report

Merging #23 into master will increase coverage by 0.49%.
The diff coverage is 71.42%.

@@            Coverage Diff             @@
##           master      #23      +/-   ##
==========================================
+ Coverage   49.01%   49.51%   +0.49%     
==========================================
  Files           1        1              
  Lines         102      103       +1     
  Branches       19       16       -3     
==========================================
+ Hits           50       51       +1     
  Misses         52       52

Impacted Files	Coverage Δ
app.js	49.51% <71.42%> (+0.49%)	⬆️

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[pavelbinar]

Thank you very much for the PR!

I had an PR from @jeremysuriel recently which was fixing the pagination as well.
See here: https://github.com/remoteorigin/git-issues-downloader/pull/20/files

I think his changes are elegant and perhaps more flexible, like: https://github.com/remoteorigin/git-issues-downloader/pull/20/files#diff-0364f57fbff2fabbe941ed20c328ef1aR123

Lest's combine your and @jeremysuriel code together to bring best of both.

I will have time to do so by start of the next week. If you would like to proceed sooner feel free to do so; just extend this PR with Jeremys code.

[pavelbinar]

Please see the updated develop