Add examples for Integer.try_convert [ci skip]

numeric.rb

@@ -233,11 +233,14 @@ end
 #    Integer.try_convert(object) -> object, integer, or nil
 #
 #  If +object+ is an \Integer object, returns +object+.
+#    Integer.try_convert(1) # => 1
 #
 #  Otherwise if +object+ responds to <tt>:to_int</tt>,
 #  calls <tt>object.to_int</tt> and returns the result.
+#    Integer.try_convert(1.25) # => 1
 #
 #  Returns +nil+ if +object+ does not respond to <tt>:to_int</tt>
+#    Integer.try_convert([]) # => nil
 #
 #  Raises an exception unless <tt>object.to_int</tt> returns an \Integer object.
 #