Add support for multiple readers

[janmyszkier]

No description provided.

[mlesniew]

Thanks for your contribution, great work.

I added a few comments, would you mind making corrections before I merge it?

[janmyszkier]

@mlesniew sorry, I somehow missed those comments (I pretty much ignore issues not assigned to me directly). I'll take a look at the CR and make the adjustments today.

[janmyszkier]

@mlesniew not sure if you have seen the updated, so just ping-ing you here.

[mlesniew]

Hey, sorry I haven't look into this for so long.

Thanks for applying the requested changes. There were a few additional changes I wanted to introduce before merging, but since they were simple and this PR has been waiting for so long, I went ahead and applied them myself.

I have:

• squashed your work into just two commits and reworded the description
• removed nargs="?" from the --site parameter specification (surprisingly setting nargs this way doesn't make it work as intuitively expected)
• made some cosmetic changes to the README and the help message.

The changes are now merged into master. You're still the author of the two commits. I will soon release a new version with these changes and push it to PyPI.

Thanks for your contribution!