Lots of documentation formatting.

Started as fixing misindented definitions, then more indentations, then
a bunch of similar things (square brackets, huge spaces at end-of-lines,
etc).

original commit: d61eb53686f735b979a60dc6f9efd3d2aa9777d9

collects/scribblings/scribble/srcdoc.scrbl

@@ -117,8 +117,8 @@ form.}
                          (->d (arg ...) () #:rest id rest [id result])])]{
 
 Like @racket[proc-doc], but supporting contract forms that embed
-argument names. Only a subset of @racket[->i] and @racket[->d] forms are currently
-supported.}
+argument names. Only a subset of @racket[->i] and @racket[->d] forms are
+currently supported.}
 
 @defform[(thing-doc id contract-expr dec-expr)]{
 

collects/scribblings/scribble/xref.scrbl

@@ -163,7 +163,6 @@ Transfers cross-reference information to @racket[ci], which is the
 initially collected information from @racket[renderer].}
 
 
-
 @defproc[(xref-index [xref xref?]) (listof entry?)]{
 
 Converts indexing information @racket[xref] into a list of