docs(ambient): Document what flags are enabled when enabling ambient #16649
Description
WRT to flag ENABLE_INGRESS_WAYPOINT_ROUTING, the docs read that
If true, Gateways will call service waypoints if the 'istio.io/ingress-use-waypoint' label set on the Service.
that by default this is set to false. However, this was different than what I experienced, since labeling a namespace with ingress-use-waypoint: true was working without any configurion in an Ambient installation. When I asked in istio slack, I got the response that
The feature is now enabled by default when installing with the ambient enabled
...
Enabling ambient mode also includes a number of features which are relevant to ambient functioning
IMO this information is crucial and should be part of the ambient docs.