Add information on performing correct scientific attribution

[erwan-privat]

Your Godot version:

Godot 4.4.1-stable, but not really relevant.

Issue description:

I've been working on a academic educational chemistry software using Godot. I would like to properly give credits. This is not the main use-case of this software, but I know of some other scientists or content creators who also use Godot for scientific visualizations. The documentation should have a page with a bibtex entry or a recommended way to properly cite Godot in scientific papers.

URL to the documentation page (if already existing):

None that I could find, except for maybe the Licence section of https://github.com/godotengine/godot-docs?tab=readme-ov-file relevant passage quoted here:

With the exception of the classes/ folder, all the content of this repository is licensed under the Creative Commons Attribution 3.0 Unported license (CC BY 3.0) and is to be attributed to "Juan Linietsky, Ariel Manzur and the Godot community". See LICENSE.txt for details.

I propose something along the lines of

@misc{godot,
  title = {{Godot engine v4.4.1-stable}},
  author = {Juan Linietsky and Ariel Manzur and {the Godot community}},
  url = {https://godotengine.org/},
  year = {2025}
}

[Calinou]

We can probably add something on index.rst below the Get involved section, or add it to an expandable section in the footer below the license notice (using <details>).

For example:

<details>
<summary>Citation information</summary>

<!-- `$version` and `$year` should be replaced by their actual values at build-time, or at runtime in JavaScript if this isn't feasible. -->
<pre>
<code>
@misc{godot,
  title = {{Godot Engine $version}},
  author = {Juan Linietsky and Ariel Manzur and {the Godot community}},
  howpublished = {https://godotengine.org/},
  year = {$year}
}
</code>
</pre>

[erwan-privat]

I made a mistake in my example, the url field should be replaced by the non-optional howpublished one as such

@misc{godot,
  title = {{Godot Engine $version}},
  author = {Juan Linietsky and Ariel Manzur and {the Godot community}},
  howpublished = {https://godotengine.org/},
  year = {$year}
}