Additional alias `readOnly` for the `ro` pragma
Heyho

Right now, the `ro` pragma already exists to define models that should only be used to read data from the database. 
However, a new user of the library might not anticipate to find that pragma under its abbreviation `ro`.
Thus I would like to ask for an additional alias `readOnly` that fulfills the same function as `ro`, but with a more expressive name.