[Merged by Bors] - chore(Algebra/Category): clean up erw and porting notes

[Vierkantor]

I searched for erw and porting note and did my best to fix them. We still have lots of ugly erws in (presheaves of) ModuleCat, unfortunately...

---

[github-actions]

PR summary efcf3d9e50

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ RingHom.smul_toAlgebra
- instance (G : Grp) : Group G.carrier

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.

---

Decrease in tech debt: (relative, absolute) = (9.76, 0.01)

Current number	Change	Type
3322	-27	porting notes
1303	-3	erw

Current commit efcf3d9e50
Reference commit f410b48e6f

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).

[adomani]

This looks good to me, thanks!

I'll let someone else actually merge the PR, since I do not know too well category theory in mathlib.

[joelriou]

Thanks!

bors merge

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

• Build
• Lint style