[doc] Add a missing comma
diff --git a/src/hb-paint.h b/src/hb-paint.h
index 0e09696..98e0dc0 100644
--- a/src/hb-paint.h
+++ b/src/hb-paint.h
@@ -269,7 +269,7 @@
*
* This method is called for glyphs with image blobs in the CBDT,
* sbix or SVG tables. The @format identifies the kind of data that
- * is contained in @image. Possible values include #HB_PAINT_IMAGE_FORMAT_PNG
+ * is contained in @image. Possible values include #HB_PAINT_IMAGE_FORMAT_PNG,
* #HB_PAINT_IMAGE_FORMAT_SVG and #HB_PAINT_IMAGE_FORMAT_BGRA.
*
* The image dimensions and glyph extents are provided if available,
