Readded relevant description

Author: Chillee

content/geometry/onSegment.h

@@ -3,7 +3,7 @@
  * Date: 2019-04-26
  * License: CC0
  * Source: https://vlecomte.github.io/cp-geo.pdf
- * Description: Returns true iff p lies on the line segment from s to e. Intended for use with e.g. Point<long long> where overflow is an issue.
+ * Description: Returns true iff p lies on the line segment from s to e. Intended for use with e.g. Point<long long> where overflow is an issue.  Use (segDist(s,e,p)<=epsilon) instead when using Point<double>.
  * Status:
  */
 #pragma once