Small doc updates

docs/en/SkiaSharp/GRContextFlushBits.xml

@@ -18,7 +18,7 @@
   </Attributes>
   <Docs>
     <summary>
-      <para />
+      <para></para>
     </summary>
     <remarks>
       <para></para>

docs/en/SkiaSharp/SKBitmap.xml

@@ -1250,7 +1250,7 @@
         <param name="ctable">The color table to use, if installing <see cref="F:SkiaSharp.SKColorType.Index8" /> pixels.</param>
         <param name="releaseProc">The delegate to invoke when the pixels are no longer referenced.</param>
         <param name="context">The user data to use when invoking the delegate.</param>
-        <summary>Installs the specified pixels into the bitmap.</summary>
+        <summary>Installs the specified pixels into the bitmap, with an option to release the pixel buffer upon completion.</summary>
         <returns>Returns true on success, or false on failure. If there was an error, the bitmap will be set to empty.</returns>
         <remarks>
           <para></para>

docs/en/ns-SkiaSharp.xml

@@ -1,6 +1,10 @@
 <Namespace Name="SkiaSharp">
   <Docs>
     <summary>SkiaSharp is a 2D graphics API powered by the Skia library.</summary>
-    <remarks>For information on getting started with the SkiaSharp library, please visit the Xamarin documentation website.</remarks>
+    <remarks>
+      <para>The SkiaSharp provides a compelte set of APIs to render 2D images.   Usually you start by creating a surface with <see cref="T:SkiaSharp.SKSurface" />, obtain an <see cref="T:SkiaSharp.SKCanvas" /> from it, and issue drawing commands there.  You can then access the underlying bitmap, or get it encoded as an image.</para>
+      <para />
+      <para />
+    </remarks>
   </Docs>
 </Namespace>