preliz conversion from Prior fails with specific distributions

[aloctavodia]

For example Prior("Truncated", dist=Prior("Normal", mu=0, sigma=1), lower=0, upper=1).preliz

The next release of PreliZ will support Prior objects; many functions will directly accept a Prior distribution as input (see here and here). Like pz.plot(Prior("Normal", mu=0, sigma=1))

Additionally, a new function pz.from_prior will be available. The preliz method from Prior could be updated to use pz.from_prior or the method could be removed, and a mention of PreliZ and/or a link to the PreliZ example could be added.