Update Authors & Acknowledgements and Bibliography for v0.5

[gefux]

There will be lot's of new contributors for version 0.5.
We should then update the list of contributers and papers.

[piperfw]

Oh good, saves me having to make a new issue. Note several of the preprints have since become publications. Do we want to change those for 0.5?
I would also be tempted to update the dates to reflect the latest publication dates e.g.

- **[Strathearn2019]** Strathearn,
  *Modelling Non-Markovian Quantum Systems Using Tensor Networks*,
  `Springer Theses <http://link.springer.com/10.1007/978-3-030-54975-6>`_
  (2020).

should really be Strathearn2020

[gefux]

Fixed with PR #135