minor fix on readSTL documentation

Former-commit-id: 122fd8bad5d169eea956c3d651e7cd9d33184903

include/igl/readSTL.h

@@ -23,9 +23,9 @@ namespace igl
   //   Scalar  type for positions and vectors (will be read as double and cast
   //     to Scalar)
   // Inputs:
-  //   filename path to .obj file
+  //   filename path to .stl file
   // Outputs:
-  //   V  double matrix of vertex positions  #F*3 by 3
+  //   V  double matrix of vertex positions  #V*3 by 3
   //   F  index matrix of triangle indices #F by 3
   //   N  double matrix of vertex positions  #F by 3
   // Returns true on success, false on errors