Docs: portuguese version

[geankaminski]

Hello,
I intend to start translating the documentation into Portuguese. starting with the manual section

[geankaminski]

I'll continue with the reference section (Animation, Animation / Tracks, Audio, Cameras & Constants).

[mrdoob]

We currently have a problem with documentation translations: #24984

[Mugen87]

With r175 there will be a new documentation based on JSDoc. The new docs cover the entire code base (core+addons) and support new features like client-side search. However, since the documentation is generated via JSDoc, there is no i18n support. The pages are only available in English.

Translated versions of the documentation are not maintained in this repository anymore, see #24984.