Implement policies with each vault

Similarly to the `read me` file in a Git repository, in a vault, there would be a `policies` files where is described how to unlock the vault, who owns it, etc.

Start by reviewing the repository's README and the issue's proposed policies file concept. Define what each vault policy must describe, including how to unlock the vault and who owns it; the work is done when every vault has a policy file with those details.

Written by the indexing model from the issue text.