offapi: update XCanvas::createFont parameter description.

Recognized parameters of aExtraFontProperties were not implemented as
documented. Update the document to reflect current implementation.

Change-Id: I001beb8843161c7633830b7ec64a79695ea0f091
Reviewed-on: https://gerrit.libreoffice.org/62510
Tested-by: Jenkins
Reviewed-by: Mark Hung <marklh9@gmail.com>

offapi/com/sun/star/rendering/XCanvas.idl

@@ -464,26 +464,10 @@ interface XCanvas : ::com::sun::star::uno::XInterface
         @param aExtraFontProperties
         Additional font properties to be applied when selecting this
         font. Normally, you should not need this parameter. Currently,
-        the following properties are recognized:
-
-        -   Kerning: a double between 0 and 1, where
-            0 completely disables kerning. Whether kerning is on or
-            off by default is font-dependent.
-
-        -   IsEmphasisMarks: a boolean, where `TRUE`
-            enables automatic placements of emphasis marks, e.g. for
-            Hebrew. The default value, if this property is not
-            specified, is `FALSE`.
-
-        -   ExpandedSpacing: a double value which is added
-            between all cell distances for this font. The default value for
-            this property is zero. Use negative values for condensed output,
-            and positive values for expanded output.
-
-        -   OptionalLayoutFeatures: a sequence of
-            ::com::sun::star::beans::PropertyValue listing
-            font-specific optional layout features, like glyph
-            variants.
+        the following property is recognized:
+
+        -   EmphasisMark: long integer that represents the emphasis mark.
+            @see ::com::sun::star::awt::FontEmphasisMark
 
         @param aFontMatrix
         Font-specific transformation matrix, which affects both the