Things need to be stored in a volume, so we also add a bunch of configuration options for moving the persistence around.

This commit adds a new section and option in config.yaml for rooms and whether
they should be shown in the HS' public directory listing by default.

The default behavior is to show them.

These are negative flags so that existing configurations can still work without modification. Otherwise the fields would be required and potentially break existing installs.

this avoids parse errors