COMP: fix documentation build warnings

Author: jadh4v

src/Filtering/MathematicalMorphology/DilateUsingFunctionalGrayscale/Documentation.rst

@@ -1,7 +1,7 @@
 :name: DilateUsingFunctionalGrayscale
 
 Dilate a grayscale image using a functional kernel
-========================
+===================================================
 
 .. index::
   single: BinaryBallStructuringElement

src/Filtering/MathematicalMorphology/index.rst

@@ -6,6 +6,7 @@ MathematicalMorphology
 
   CreateABinaryBallStructuringElement/Documentation.rst
   DilateAGrayscaleImage/Documentation.rst
+  DilateUsingFunctionalGrayscale/Documentation.rst
   ErodeAGrayscaleImage/Documentation.rst
   ErodeBinaryImageUsingFlatStruct/Documentation.rst
   GenerateStructureElementsWithAccurateArea/Documentation.rst