Add include directories to doxygen documentation.

Author: dhebbeker

Doxyfile

@@ -871,7 +871,14 @@ WARN_LOGFILE           =
 # spaces. See also FILE_PATTERNS and EXTENSION_MAPPING
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  =
+INPUT                  = .
+INPUT += /home/dhebbeker/.arduino15/packages/esp8266/hardware/esp8266/2.7.4/cores/esp8266
+INPUT += /home/dhebbeker/Arduino/libraries/SimplyAtomic
+INPUT += /home/dhebbeker/.arduino15/packages/esp8266/hardware/esp8266/2.7.4/variants/generic
+INPUT += /home/dhebbeker/.arduino15/packages/esp8266/hardware/esp8266/2.7.4/libraries/ESP8266WebServer/src
+INPUT += /home/dhebbeker/.arduino15/packages/esp8266/hardware/esp8266/2.7.4/libraries/Wire
+INPUT += /home/dhebbeker/Arduino/libraries/MCP23017/src
+INPUT += /home/dhebbeker/Arduino/libraries/VL53L1/src
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
@@ -2518,7 +2525,7 @@ DIRECTORY_GRAPH        = YES
 # The default value is: png.
 # This tag requires that the tag HAVE_DOT is set to YES.
 
-DOT_IMAGE_FORMAT       = png
+DOT_IMAGE_FORMAT       = svg
 
 # If DOT_IMAGE_FORMAT is set to svg, then this option can be set to YES to
 # enable generation of interactive SVG images that allow zooming and panning.
@@ -2604,7 +2611,7 @@ MAX_DOT_GRAPH_DEPTH    = 0
 # Minimum value: 0, maximum value: 1000, default value: 1.
 # This tag requires that the tag DIRECTORY_GRAPH is set to YES.
 
-MAX_DOT_GRAPH_SUCCESSOR= 1
+MAX_DOT_GRAPH_SUCCESSOR= 3
 
 # Set the DOT_TRANSPARENT tag to YES to generate images with a transparent
 # background. This is disabled by default, because dot on Windows does not seem