doc/fate: Rework examples to a section of its own

  Make it easier to spot the example. This way it can already be
discovered by scanning the table of contents.

doc/fate.texi

@@ -187,7 +187,8 @@ the synchronisation of the samples directory.
     through @command{ssh}.
 @end table
 
-Example:
+@section Examples
+
 @example
 make V=1 SAMPLES=/var/fate/samples THREADS=2 CPUFLAGS=mmx fate
 @end example