Update PPVM editor label

src/Editors/VideoManifestEditor.vala

@@ -47,7 +47,7 @@ namespace Publicate.Editors {
             group.margin_end = 18;
             group.margin_start = 18;
             group.margin_top = 18;
-            group.title = "Publication Details";
+            group.title = "Video Details";
             group.description = "";
 
             master = new FileChooserRow (window);