driver: rename docker to docker-container

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

cmd/buildx/main.go

@@ -8,7 +8,7 @@ import (
 	"github.com/tonistiigi/buildx/commands"
 	"github.com/tonistiigi/buildx/version"
 
-	_ "github.com/tonistiigi/buildx/driver/docker"
+	_ "github.com/tonistiigi/buildx/driver/docker-container"
 )
 
 func main() {

driver/docker-container/factory.go

@@ -15,11 +15,11 @@ type factory struct {
 }
 
 func (*factory) Name() string {
-	return "docker"
+	return "docker-container"
 }
 
 func (*factory) Usage() string {
-	return "docker"
+	return "docker-container"
 }
 
 func (*factory) Priority() int {