boards/nucleo-g431rb & g474re: add pinouts to boards doc page

[krzysztof-cabaj]

Contribution description

This PR adds pinouts to the documentation pages for:

• nucleo-g431rb
• nucleo-g474re

Testing procedure

Generate doc and see if everything is fine.

make doc
xdg-open doc/doxygen/html/group__boards__nucleo-g431rb.html
xdg-open doc/doxygen/html/group__boards__nucleo-g474re.html

Issues/PRs references

None

[riot-ci]

Murdock results

✔️ PASSED

aff4bd4 boards/nucleo-g474re: add pinout to doc page

Success	Failures	Total	Runtime
1	0	1	01m:17s

Artifacts

• Documentation preview

[chrysn]

So far we're usually external image inclusion from their original sources in hopes that that makes copyright handling easier (it probably does because we don't copy them into a repo of which we claim it is LGPL unless noted otherwise). Is there a source we could use here?

(I'm aware that that approach is not great from a privacy PoV, but I don't have easy alternatives at hand that don't require more administrative work to correctly annotate data we think we can copy under Fair Use or any European equivalent to that US legal construct that I'm not aware of.)

[chrysn]

Preview deep link: https://ci.riot-os.org/results/21464bfd956845de940216874054000a/doc-preview/group__boards__nucleo-g431rb.html / https://ci.riot-os.org/results/21464bfd956845de940216874054000a/doc-preview/group__boards__nucleo-g474re.html

[krzysztof-cabaj]

@chrysn thanks for valuable comment.

Unfortunately, I cannot find these pinouts in other webpages as images or svg schematics.
I extract them directly from the STM Board Manual - and from few recent PR I add clear
statement "from STM board manual". Maybe solution for this issue will be more detailed
description, for example, "from STM user manual, UM2505/link to pdf/, page 29"?

[krzysztof-cabaj]

@benpicco, @chrysn thanks for support!

Do you think that adding clear source of pinouts will be beneficial for doc/project? I could do this for STM boards.

[chrysn]

Yes, any image we use (linked or included) will be better with an accurate source description; ping me in any PRs for ACKs.