Forgot to change png to jpg

Author: trevordblack

books/RayTracingInOneWeekend.html

@@ -1889,7 +1889,7 @@
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     [Listing [random-unit-vector]: <kbd>[vec3.h]</kbd> The random_unit_vector() function]
 
-  ![Figure [rand-unitvec]: Generating a random unit vector](../images/fig-1.10-rand-unitvec.png)
+  ![Figure [rand-unitvec]: Generating a random unit vector](../images/fig-1.10-rand-unitvec.jpg)
 
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