use pmap in literate examples

[jpfairbanks]

The examples might not have been updated to component arrays, but this will compute all the examples in parallel if you have multiple threads of julia running

[lukem12345]

@quffaro Are our actions launched with julia --threads=auto, or some environment variable accomplishing the same set?

[quffaro]

Currently, the .github repo does not pass a thread flag. Our branch for standing up buildkite #186 (feature-buildkite) is currently passing a request to srun for 32 cores and julia -t 32 in the script it executes.

[lukem12345]

This will likely close issue #174 on merging