0.8.0

Added

• MqttProfile::MqttConfig gains haDiscovery, a flag for whether the
  application should publish Home Assistant MQTT discovery messages. Topics
  remain absent by design: those are project-specific addresses, while this is a
  yes/no about a broker-side convention. A base field rather than a subclass's
  because it has no natural siblings — a second convention would make it an enum
  rather than add a second boolean — and because a derived field is invisible to
  MqttConfigComponent, which works through MqttConfig.
• NetworkProfileVersion.h defines NETWORK_PROFILE_VERSION as
  major * 10000 + minor * 100 + patch, so a consumer can require a minimum
  version at compile time. Libraries built on this one deliberately do not
  declare it as a dependency — AsyncConfigPortal's network and MQTT modules are
  opt-in — so a manifest entry cannot express the constraint and the check has
  to live in the source. An undefined macro is 0 in #if, so the same test also
  catches the releases from before this header existed.
  Carried by _doSave(), _doLoad() and toJson(); defaults to false, so
  records written before the field existed load as "off", which is what those
  devices were doing.