Improve config failure error message.

api/internal/target/kusttarget.go

@@ -364,7 +364,8 @@ func (kt *KustTarget) configureBuiltinPlugin(
 	}
 	err = p.Config(resmap.NewPluginHelpers(kt.ldr, kt.validator, kt.rFactory), y)
 	if err != nil {
-		return errors.Wrapf(err, "builtin %s config: %v", bpt, y)
+		return errors.Wrapf(
+			err, "trouble configuring builtin %s with config: `\n%s`", bpt, string(y))
 	}
 	return nil
 }

cmd/config/internal/generateddocs/api/docs.go

@@ -308,8 +308,7 @@ An example using ` + "`" + `v1/List` + "`" + ` as input:
 	apiVersion: v1
 	kind: List
 	items:
-	  spec:
-	   - apiVersion: foo-corp.com/v1
+	  - apiVersion: foo-corp.com/v1
 	    kind: FulfillmentCenter
 	    metadata:
 	      name: staging