22 sector names

[georgerichardson]

Uses tf-idf and embedding cosine similarity to create names for text sectors (after reassignment).

closes #22

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Checklist:

• [x] I have refactored my code out from notebooks/
• [x] I have run flake8 and addressed any linter erors
• [x] I have checked the code runs
• [ ] I have tested the code
• [ ] I have run pre-commit and addressed any issues not automatically fixed
• [x] I have rebased onto dev (or merged any new changes from dev)
• [x] I have documented the code
  • [x] Major functions have docstrings
  • [ ] Appropriate information has been added to READMEs
• [x] I have explained the feature in this PR or (better) in output/reports/
• [x] I have requested a code review