add esl to Doxygen.conf

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@14540 d0543943-73ff-0310-b7d9-9358b9ac24b2

docs/Doxygen.conf

@@ -83,7 +83,7 @@ WARN_LOGFILE           =
 #---------------------------------------------------------------------------
 # configuration options related to the input files
 #---------------------------------------------------------------------------
-INPUT                  = ../src ../src/include ../src/include/private
+INPUT                  = ../src ../src/include ../src/include/private ../libs/esl/src ../libs/esl/src/include
 FILE_PATTERNS          = *.c \
                          *.cc \
                          *.cxx \