[CMake] doxygen use mathjax

CMakeLists.txt

@@ -25,6 +25,7 @@ SET(PROJECT_DESCRIPTION "jrl-walkgen bindings for dynamic-graph.")
 SET(PROJECT_URL "https://github.com/stack-of-tasks/sot-pattern-generator")
 
 SET(CUSTOM_HEADER_DIR "${PROJECT_NAME}")
+SET(DOXYGEN_USE_MATHJAX YES)
 
 # Disable -Werror on Unix for now.
 SET(CXX_DISABLE_WERROR True)