Add 'modules' to doxygen generation.

Bug: skia:
Change-Id: Ia64aa8e8e75d0ed3a88dd34e63fc22c65cf9acc9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/217816
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Commit-Queue: Joe Gregorio <jcgregorio@google.com>
diff --git a/tools/doxygen/Doxyfile b/tools/doxygen/Doxyfile
index 92bd12b..ada9cf1 100644
--- a/tools/doxygen/Doxyfile
+++ b/tools/doxygen/Doxyfile
@@ -790,7 +790,16 @@
 # spaces. See also FILE_PATTERNS and EXTENSION_MAPPING
 # Note: If this tag is empty the current directory is searched.
 
-INPUT = ../../include/core ../../include/effects ../../include/gpu ../../include/pathops ../../third_party/skcms ./mainpage
+INPUT = ../../include/core \
+  ../../include/effects \
+  ../../include/gpu \
+  ../../include/pathops \
+  ../../third_party/skcms \
+  ../../modules/particles/include \
+  ../../modules/skottie/include \
+  ../../modules/sksg/include \
+  ../../modules/skshaper/include \
+  ./mainpage
 
 # 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