Version 3.6.0 released

Version 3.6.0 cleans up the code and interface around sorting. The `Encyclopaedia.sort()` method has been added and the `Encyclopaedia.Sort()` action now uses it. Methods and properties which should have been private now can't be changed. This should reduce the chance a developer shoots themselves in the foot. The use of the `SortMode` enum is standardised and has better documentation.

Full list of changes available at: https://renpy-encyclopaedia.readthedocs.io/en/latest/development/changelog.html