Display badge for targetType appropriate to release

So if we're looking at:

https://index.scala-lang.org/typelevel/cats/cats-core/2.6.1?target=_sjs1.x_3.x

...we want to see the badge with `targetType=js`, rather than the default
badge that displays JVM-based artifacts.

model/src/main/scala/ch.epfl.scala.index.model/Release.scala

@@ -230,7 +230,8 @@ object Release {
 
     def artifactHttpPath = s"/$organization/$repository/$artifact"
     def artifactFullHttpUrl = s"https://index.scala-lang.org$artifactHttpPath"
-    def badgeUrl: String = s"$artifactFullHttpUrl/latest-by-scala-version.svg"
+    def nonDefaultTargetType: Option[ScalaTargetType] = target.map(_.targetType).filter(_ != Jvm)
+    def badgeUrl: String = s"$artifactFullHttpUrl/latest-by-scala-version.svg" + nonDefaultTargetType.map(tt => s"?targetType=$tt").mkString
     def httpUrl = {
       val targetQuery = target.map(t => s"?target=${t.encode}").getOrElse("")