[stv cleanup] Add note. Not sure whether the StvPPVertex finder has b…

…een used outside of Stv R&D. So keeping this for now.

StRoot/StGenericVertexMaker/StGenericVertexMaker.cxx

@@ -19,11 +19,17 @@
 #include "StGenericVertexMaker/StGenericVertexMaker.h"
 #include "StGenericVertexMaker/StiPPVertex/StPPVertexFinder.h"
 #include "StGenericVertexMaker/StppLMVVertexFinder.h"
-#include "StGenericVertexMaker/StvPPVertex/StPPVertexFinder.h"
+#include "StGenericVertexMaker/StvPPVertex/StPPVertexFinder.h" 
 #include "St_base/StMessMgr.h"
 #include "St_db_Maker/St_db_Maker.h"
 #include "tables/St_g2t_vertex_Table.h"
 
+// Historical Note 10/17/23.  Jason Webb
+// -------------------------------------
+// The StvPPVertex appears to be an equivalent set of vertex
+// finding algorithms using tracks from the StEvent data model 
+// rather than the internal data structures of the Sti tracker.
+
 class StMuDst;
 class TClonesArray;