[Docs] Add missing code block (#44094)

* [Docs] Add missing code block

* Fix block order

Author: jeremiahpslewis

base/abstractarray.jl

@@ -2126,7 +2126,9 @@ julia> hvncat(((3, 3), (3, 3), (6,)), true, a, b, c, d, e, f)
  4  5  6
 ```
 
+
 # Examples for construction of the arguments:
+```julia
 [a b c ; d e f ;;;
  g h i ; j k l ;;;
  m n o ; p q r ;;;
@@ -2143,6 +2145,7 @@ julia> hvncat(((3, 3), (3, 3), (6,)), true, a, b, c, d, e, f)
  _____________
  4             = elements in each 4d slice (4,)
  => shape = ((2, 1, 1), (3, 1), (4,), (4,)) with `rowfirst` = true
+```
 """
 hvncat(dimsshape::Tuple, row_first::Bool, xs...) = _hvncat(dimsshape, row_first, xs...)
 hvncat(dim::Int, xs...) = _hvncat(dim, true, xs...)