remove obsolete example (#246)

pollen/private/ts.rktd

@@ -1 +1 @@
-1613427909
+1613429435

pollen/scribblings/decode.scrbl

@@ -44,17 +44,6 @@ This function doesn't do much on its own. Rather, it provides the hooks upon whi
 
 Recall that in Pollen, all @secref["tags-are-functions"]. By default, the @racket[_tagged-xexpr] from a source file is tagged with @racket[root]. So the typical way to use @racket[decode] is to attach your decoding functions to it, and then define @racket[root] to invoke your @racket[decode] function. Then it will be automatically applied to every @racket[doc] during compile. 
 
-For instance, here's how @racket[decode] is attached to @racket[root] in @link["http://practicaltypography.com"]{@italic{Butterick's Practical Typography}}. There's not much to it —
-
-@racketblock[
-(define (root . items)
-  (decode (txexpr 'root '() items)
-          #:txexpr-elements-proc decode-paragraphs
-          #:block-txexpr-proc (compose1 hyphenate wrap-hanging-quotes)
-          #:string-proc (compose1 smart-quotes smart-dashes)
-          #:exclude-tags '(style script)))
-          ]
-
 @margin-note{The @racket[hyphenate] function is not part of Pollen, but rather the @link["http://github.com/mbutterick/hyphenate"]{@racket[hyphenate] package}, which you can install separately.}
 
 This illustrates another important point: even though @racket[decode] presents an imposing list of arguments, you're unlikely to use all of them at once. These represent possibilities, not requirements. For instance, let's see what happens when @racket[decode] is invoked without any of its optional arguments.