Reformat theory of operations and add BibTeX citations

[tsalo]

Closes none. Apologies for the second unsolicited PR in one day.

Changes proposed in this pull request:

• Add sphinxcontrib-bibtex to the list of documentation dependencies and configure it to allow in-text citations in the documentation.
• Reformat theoryofoperation.rst a bit to split up lines on punctuation.
• Add a tip that increasing the number of passes will improve your results. I don't actually know if this is true.

[bbfrederick]

I generally find that using more passes than three doesn't change much, but it doesn't make things worse... I think the way you wrote it is fine and conveys that.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 34.55%. Comparing base (bd2d5e9) to head (563365e). Report is 17 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #173 +/- ## ========================================== - Coverage 34.56% 34.55% -0.01% ========================================== Files 135 135 Lines 24335 24335 Branches 3503 3503 ========================================== - Hits 8411 8409 -2 - Misses 15129 15130 +1 - Partials 795 796 +1 ```

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