added functionality for extracting distinct keywords from list of strings

[Viole-Grace]

changes:

• added function to abstract running list of input strings or a single string
• optimised performance by incorporating nlp.pipe() to form doc, which grants speed advantages for longer doc / large number of input strings
• updated testing notebook with examples of multiple string extraction
• updated readme to reflect latest changes for single string keyword extraction + multiple string keyword extraction

[sahyagiri]

Thanks a lot for the pull request. At present I plan to keep the API simple with single document and single set of keywords.

• For multiple documents, can you create a wrapper function, say "distinct_keywords.get_multiple_doc_keywords(docs) ?
• Keep the example notebook minimal
• I would welcome any step for single document keyword extraction, that is making it faster and consistent over larger documents

[Viole-Grace]

changes:

• added separate functions for running a list of input strings or a single string
• optimised performance by incorporating nlp.pipe() to form doc, which grants speed advantages for longer doc / large number of input strings for both functions
• updated testing notebook with examples of multiple string extraction
• updated readme to reflect latest changes for single string keyword extraction + multiple string keyword extraction