Clean up some documentation

[docwhat]

What type of PR is this?

• documentation

What this PR does / why we need it:

Improve the pkg.go.dev documentation.

Which issue(s) this PR fixes:

None.

Release Notes

-->

NONE

[dearchap]

@docwhat Can you run make diffcheck and/or make v3approve ?

[docwhat]

@docwhat Can you run make diffcheck and/or make v3approve ?

Sure!

❯ make diffcheck
go run internal/build/build.go  diffcheck
# ---> /usr/bin/git rev-parse --show-toplevel
# ---> /usr/bin/git diff --exit-code
# ---> /usr/bin/git diff --cached --exit-code
❯ make v3approve
go run internal/build/build.go  v3approve
# ---> /usr/bin/git rev-parse --show-toplevel
# ---> /bin/cp -v godoc-current.txt testdata/godoc-v3.x.txt
godoc-current.txt -> testdata/godoc-v3.x.txt
❯ git status --short --branch --show-stash
## before-after-docs...docwhat/before-after-docs
❯

What is supposed to do something?

Or is the output what we want?

[avorima]

@docwhat You need make generate v3approve. When you change the godoc, files need to be re-generated.

[dearchap]

Thank you @docwhat