Updated README.md

[ktakeda1]

Added acknowledgements section

Write a detailed description of your PR here.

Please follow the guidelines for PRs contained here. Checklist:

• Ensure that your PR is small, and implements one change.
• Add unit tests for all functions that you introduced or modified.
• Run PyCharm's code cleanup tools on your Python files.
• Link the correct GitHub issue for tracking.
• Update the Changelog file: Describe your change in terms of
  Added/Changed/Removed/... in the "Upcoming" section.
• When merging your PR, replace the default merge message with a description of your PR,
  and if needed a motivation why that change was required.

[ktakeda1]

Acknowledgement text prettified and URL made live

[fepegar]

Apologies for the many changes in my commit, that was my IDE cleaning up trailing whitespaces. I just meant to fix a typo and format the citation!