Docstring linting cleanup

[Zeitsperre]

Pull Request Checklist:

• [ ] This PR addresses an already opened issue (for bug fixes / features)
  • This PR fixes issue #xyz
• [x] Tests for the changes have been added (for bug fixes / features)
• [ ] Documentation has been added / updated (for bug fixes / features)
• [x] HISTORY.rst has been updated (with summary of main changes)
• [x] I have added my relevant user information to AUTHORS.md

What kind of change does this PR introduce?:

• Updates pre-commit hooks, pins linting tools to their pre-commit equivalents
• Adds a configuration for codespell
• Fixes a few docstrings, specifies some class methods as static methods
• Renames a few internal variables for clarity, rephrased a few sentences for grammar/spelling

Does this PR introduce a breaking change?:

No.

Other information:

https://github.com/codespell-project/codespell

[coveralls]

Pull Request Test Coverage Report for Build 7846047808

• -3 of 32 (90.63%) changed or added relevant lines in 3 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.03%) to 72.656%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
clisops/ops/base_operation.py	15	18	83.33%
<!--	Total:	29	32	90.63%	-->

Files with Coverage Reduction	New Missed Lines	%
clisops/ops/average.py	1	81.25%
<!--	Total:	1		-->

Totals
Change from base Build 7844594970:	0.03%
Covered Lines:	1767
Relevant Lines:	2432

---

💛 - Coveralls

[cehbrecht]

@Zeitsperre can we merge PR #319 before this one?