docs: [solar] Add satellite imagery to rgb_url description

packages/google-maps-solar/protos/google/maps/solar/v1/solar_service.proto

@@ -595,7 +595,7 @@ message DataLayers {
   // (where we don't have data) are stored as -9999.
   string dsm_url = 3;
 
-  // The URL for an image of RGB data (aerial photo) of the region.
+  // The URL for an image of RGB data (aerial or satellite photo) of the region.
   string rgb_url = 4;
 
   // The URL for the building mask image: one bit per pixel saying whether that
@@ -721,6 +721,15 @@ enum SolarPanelOrientation {
 }
 
 // Specifies pre-GA experiments that can be enabled in the API.
+//
+// Requests using this field are classified as a pre-GA offering
+// under the [Google Maps Platform Service Specific
+// Terms](https://cloud.google.com/maps-platform/terms/maps-service-terms). See
+// [launch stage
+// descriptions](https://cloud.google.com/maps-platform/terms/launch-stages) for
+// more details.
+//
+// New values may be added to this enum in the future.
 enum Experiment {
   // No experiments are specified.
   EXPERIMENT_UNSPECIFIED = 0;