Add entries for Gabriel M. Dutra (dutra)

[dutra]

Summary

New committer (ports): Gabriel M. Dutra, dutra@

Committer's Guide, steps for new committers, steps 1–4.

Approved by: dbaio (mentor)
Approved by: garga (mentor)

[garga]

Please add the commit log message you plan to use o summary so we can review that too

shared/authors.adoc

3711–3713

As mentioned on header, this list must be kept sorted in alphabetical order by entity name

[garga]

shared/contrib-committers.adoc

396

To understand the position you will add your entry here, you must go to https://docs.freebsd.org/en/articles/contributors/ to check expanded webpage and find your spot keeping sorted by lastname

[garga]

Commit log message will need to have one line with Approved by: NICKNAME (mentor) where NICKNAME will be garga or dbaio, depending who approved the patch

shared/authors.adoc

3713

This block is still out of order

[garga]

LGTM. Just remember to deduplicate Approved by line