[Merged by Bors] - doc(Combinatorics): fix typos

[harahu]

Found with the help of Codex.

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[github-actions]

PR summary 4e56e21745

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

No declarations were harmed in the making of this PR! 🐙

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

./scripts/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[grunweg]

Thanks for your PR. Can you fix the build, please?

[harahu]

Done 👍

-awaiting-author

[grunweg]

Thanks!
bors merge

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

• Build
• Lint style
• Post-Build Step

[harahu]

Btw, @grunweg, I think it was a wise call of you to just drop the part of this PR you were unconvinced by in order to facilitate a speedy merge. If you encounter similar cases again, please know that I'm very comfortable with you trimming down the PR without my permission. It is trivial for me to create a separate PR from history, should I want to.

[grunweg]

Thanks; it's good to hear this is fine. (I was slightly hesitant.)

If you really think this is a typo (and you might be perfectly fine!), please create a separate PR. That's just not a PR I'm feeling comfortable to merge, and letting 19 typo fixes grow stale because of that one seemed to be not the trade-off we want.