v0.5.1

• Added a page about leveraging CountVectorizer and KeyphraseVectorizers
  • Shoutout to @TimSchopf for creating and optimizing the package!
  • The KeyphraseVectorizers package can be found here
• Fixed Max Sum Similarity returning incorrect similarities #92
  • Thanks to @kunihik0 for the PR!
• Fixed out of bounds condition in MMR
  • Thanks to @artmatsak for the PR!
• Started styling with Flake8 and Black (which was long overdue)
  • Added pre-commit to make following through a bit easier with styling