chore: stub out shorts creator class

src/StreamShorts.Library/Media/Video/IShortsCreator.cs

@@ -0,0 +1,5 @@
+namespace StreamShorts.Library.Media.Video;
+
+public interface IShortsCreator
+{
+}

src/StreamShorts.Library/Media/Video/ShortsCreator.cs

@@ -0,0 +1,5 @@
+namespace StreamShorts.Library.Media.Video;
+
+public class ShortsCreator : IShortsCreator
+{
+}