Add CircleCI test-splitting workflow

[mw-kapilg]

• Adds a new CircleCI workflow to showcase test splitting
• Updates MATLAB releases and macOS config
• Includes some markdown linting

NOTE: CircleCI's free plan doesn't support parallelism for macOS cloud runners. Hence those users won't be able to use test-splitting with the current workflow's mac executor configuration. Decided not to add this info as a comment in our workflow since it will increase maintenance burden.

[tsharmaMW]

Thank you for adding this workflow! It’s going to be very helpful for our users.

[mcafaro]

Overall looks good but is CircleCI connected to this repository? I can't find the jobs on Circle to verify the workflows are running as expected.

[mw-hrastega]

Suggesting some minor tweaks.

[mw-kapilg]

To use the latest keyword, I've updated the identifier to linux-with-latest (as simply linux-latest could be misleading). Does anyone have a better name or is this fine?

[mw-kapilg]

Overall looks good but is CircleCI connected to this repository? I can't find the jobs on Circle to verify the workflows are running as expected.

There are multiple CircleCI pipelines in this repository (with custom names instead of the general config.yml) and connecting multiple pipelines requires mathworks org to install the CircleCI GitHub app. Until that is done, we need to manually verify CircleCI changes.

[mcafaro]

Overall looks good but is CircleCI connected to this repository? I can't find the jobs on Circle to verify the workflows are running as expected.

There are multiple CircleCI pipelines in this repository (with custom names instead of the general config.yml) and connecting multiple pipelines requires mathworks org to install the CircleCI GitHub app. Until that is done, we need to manually verify CircleCI changes.

The mathworks/ci-configuration-examples repo has the CircleCI app, so I would think we can get it on this repo as well. I am not a repo admin, so I can't attempt to set up Circle for this repo but what are you running into when you try? We can get in touch with the MathWorks org admin if we need to.