Fixed wrong g2_spline link

ReadMe.md

@@ -6,7 +6,7 @@ autonomous_driving_tools                        {#mainpage}
 Set of useful tools for autonomous driving of car-like robots. At the moment the tools included in this library are:
 
 * **[gradient](doc/gradient.md)**: simple implementatio  of the gradient descent algorithm.
-* **[g2_spline](doc/g2_spline.md)**: implementation of the G2 splines (quintic splines).
+* **[g2_spline](doc/g2_splines.md)**: implementation of the G2 splines (quintic splines).
 * **[dijkstra](doc/dijkstra.md)**: simple implementation of the Dijkstra algorithm.
 * **[opendrive_road](doc/opendrive.md)** : Parser for the Opendrive format.