missing description for FontMetricFlags

rearrange class descriptions to make them
appear consistently inside the #Class
declaration in the .bmh files.

Look for the descriptions there and
regenerate the .md files.

Docs-Preview: https://skia.org/?cl=46523
TBR=caryclark@google.com
Bug: skia: 6898
Change-Id: I00a176428725ef27667d3f23d76d6b7ff0cfced1
Reviewed-on: https://skia-review.googlesource.com/46523
Commit-Queue: Cary Clark <caryclark@google.com>
Reviewed-by: Cary Clark <caryclark@skia.org>
diff --git a/docs/SkCanvas_Reference.bmh b/docs/SkCanvas_Reference.bmh
index ae35142..0c86011 100644
--- a/docs/SkCanvas_Reference.bmh
+++ b/docs/SkCanvas_Reference.bmh
@@ -1,6 +1,8 @@
 #Topic Canvas
 #Alias Canvas_Reference
 
+#Class SkCanvas
+
 Canvas provides an interface for drawing, and how the drawing is clipped and transformed.
 Canvas contains a stack of Matrix and Clip values.
 
@@ -22,8 +24,6 @@
 Canvas can be constructed to draw to Bitmap without first creating Raster_Surface.
 This approach may be deprecated in the future.  
 
-#Class SkCanvas
-
 #Topic Overview
 
 #Subtopic Subtopics