Improve documentation about traversal behavior in plone.api.content.get

[idgserpro]

I just solved an intricate bug because I didn't now that plone.api.content.get uses traversal. Since you give a path as an argument, I wasn't expecting traversal in this context.

Inspired by:

plone.api comes with cookbook-like documentation and step-by-step instructions for doing common development tasks in Plone. Recipes try to assume the user does not have extensive knowledge about Plone internals.

I suggest to complement plone.api.content.get's documentation explaining about acquisition effect and, if possible, with examples of what can happen because of acquisition.