Update documentation with context receivers section?

[qwexter]

Hi! I've just learned that the context receivers feature will be phased out soon. Additionally, I found a new proposal by @serras.

What do you think about removing all mentions of context receivers from the Arrow documentation? It might be misleading to suggest using this feature now, I suppose.

@serras @nomisRev

[serras]

Such a migration is scheduled, and some of the docs have been updated. However, we're waiting for context parameters to appear in order to have examples using that feature.