Add a note to sharedarrays documentation. (#35807)

* Update distributed-computing.md

* Update doc/src/manual/distributed-computing.md

Co-authored-by: Matt Bauman <mbauman@juliacomputing.com>

Co-authored-by: Matt Bauman <mbauman@juliacomputing.com>
(cherry picked from commit 6a9ced3)

doc/src/manual/distributed-computing.md

@@ -1,4 +1,4 @@
-# Multi-process and Distributed Processing
+# Multi-processing and Distributed Computing
 
 An implementation of distributed memory parallel computing is provided by module `Distributed`
 as part of the standard library shipped with Julia.
@@ -760,7 +760,7 @@ SharedArray{T,N}(dims::NTuple; init=false, pids=Int[])
 which creates an `N`-dimensional shared array of a bits type `T` and size `dims` across the processes specified
 by `pids`. Unlike distributed arrays, a shared array is accessible only from those participating
 workers specified by the `pids` named argument (and the creating process too, if it is on the
-same host).
+same host). Note that only elements that are [`isbits`](@ref) are supported in a SharedArray.
 
 If an `init` function, of signature `initfn(S::SharedArray)`, is specified, it is called on all
 the participating workers. You can specify that each worker runs the `init` function on a distinct