doxygen allow all .cc .hh and CMakeLists.txt, not just in examples/ d…

…ir (gazebosim#198)

Signed-off-by: Mabel Zhang <[email protected]>

doc/doxygen/api.in

@@ -859,15 +859,16 @@ EXCLUDE_SYMBOLS        = detail
 # that contain example code fragments that are included (see the \include
 # command).
 
-EXAMPLE_PATH           = @CMAKE_SOURCE_DIR@/examples
+EXAMPLE_PATH           = @CMAKE_SOURCE_DIR@
 
 # If the value of the EXAMPLE_PATH tag contains directories, you can use the
 # EXAMPLE_PATTERNS tag to specify one or more wildcard pattern (like *.cpp and
 # *.h) to filter out the source-files in the directories. If left blank all
 # files are included.
 
 EXAMPLE_PATTERNS       = *.cc \
-                         *.hh
+                         *.hh \
+                         CMakeLists.txt
 
 # If the EXAMPLE_RECURSIVE tag is set to YES then subdirectories will be
 # searched for input files to be used with the \include or \dontinclude commands