[Toaster] PREFERRED_VERSION raw content for 2.0 Toaster manual

[Barros Pena, Belen]

We agreed to explain in the Toaster manual that clicking the 'build'
button in Toaster is not enough to select a certain recipe version: you
need to set PREFERRED_VERSION.

Here is some raw content for the manual.

https://www.evernote.com/shard/s4/sh/97e296c2-31fe-47c0-85f5-f567d0de013c/a
bd430ea1f20f6a1


Cheers

Belén