allow content (not just a string) for #:kind in defthing, etc.

Although commit 5415cca just made run-time checking consistent with
the documentation, the implementation turned out to allow content
before, and some existing documents relied on that. Changes the
documentation and contract to allow content, instead.

Author: mflatt

scribble-doc/scribblings/scribble/manual.scrbl

@@ -836,7 +836,7 @@ Equivalent to @racket[defmodule] variants @racket[#:no-declare].}
                          ellipses+]
                [options (code:line maybe-kind maybe-link maybe-id)]
                [maybe-kind code:blank
-                           (code:line #:kind kind-string-expr)]
+                           (code:line #:kind kind-content-expr)]
                [maybe-link code:blank
                            (code:line #:link-target? link-target?-expr)]
                [maybe-id code:blank
@@ -945,8 +945,8 @@ by the @racket[current-display-width] parameter.
 
 An optional @racket[#:kind] specification chooses the decorative
 label, which defaults to @racket["procedure"]. A @racket[#f]
-result for @racket[kind-string-expr] uses the default, otherwise
-@racket[kind-string-expr] should produce a string. An alternate
+result for @racket[kind-content-expr] uses the default, otherwise
+@racket[kind-content-expr] should produce content in the sense of @racket[content?]. An alternate
 label should be all lowercase.
 
 If @racket[#:id [src-id dest-id-expr]] is supplied, then
@@ -1007,7 +1007,7 @@ Examples:
                 pre-flow ...)
               ([options (code:line maybe-kind maybe-link maybe-id maybe-literals)]
                [maybe-kind code:blank
-                           (code:line #:kind kind-string-expr)]
+                           (code:line #:kind kind-content-expr)]
                [maybe-link code:blank
                            (code:line #:link-target? link-target?-expr)]
                [maybe-id code:blank
@@ -1028,7 +1028,7 @@ result of @racket[id-expr]) whose syntax is described by
 @racket[id], then @racket[form-datum] must have the form @racket[(id
 . _datum)].
 
-If @racket[#:kind kind-string-expr] is supplied, it is used in the
+If @racket[#:kind kind-content-expr] is supplied, it is used in the
 same way as for @racket[defproc], but the default kind is
 @racket["syntax"].
 
@@ -1338,7 +1338,7 @@ Like @racket[defparam], but the contract on a parameter argument is
                 pre-flow ...)
               ([options (code:line maybe-kind maybe-link maybe-id)]
                [maybe-kind code:blank
-                           (code:line #:kind kind-string-expr)]
+                           (code:line #:kind kind-content-expr)]
                [maybe-link code:blank
                            (code:line #:link-target? link-target?-expr)]
                [maybe-id code:blank
@@ -1348,7 +1348,7 @@ Like @racket[defparam], but the contract on a parameter argument is
 
 Like @racket[defproc], but for a non-procedure binding.
 
-If @racket[#:kind kind-string-expr] is supplied,
+If @racket[#:kind kind-content-expr] is supplied,
 it is used in the same way as for
 @racket[defproc], but the default kind is @racket["value"].
 

scribble-lib/scribble/private/manual-proc.rkt

@@ -4,7 +4,9 @@
          "../basic.rkt"
          "../manual-struct.rkt"
          (only-in "../core.rkt" 
-                  make-style make-table-columns)
+                  make-style
+                  make-table-columns
+                  content?)
          "../html-properties.rkt"
          "qsloc.rkt"
          "manual-utils.rkt"
@@ -131,7 +133,7 @@
     #:attributes (kind) ;; Expr[String/#f]
     #:description "#:kind keyword"
     (pattern (~optional (~seq #:kind k))
-             #:declare k (expr/c #'(or/c string? #f) #:name "#:kind argument")
+             #:declare k (expr/c #'(or/c content? #f) #:name "#:kind argument")
              #:with kind #'(~? k.c #f)))
 
  (define-splicing-syntax-class value-kw