Release 2025 Add doc building specification

[thomasarsouze]

We must add guidelines / documentation for publishing the documentation of the package according to the publishing status of the package. Proposition could be :

• documentation "stable" must refer to packages published in the "main" branch of conda channel "openalea3"
• documentation "vx.x.x" must refer to packages published in the "rc" branch of conda channel "openalea3"
• documentation "dev" must refer to packages published in the "dev" branch of conda channel "openalea3"