publish: embedded systems roadmap (#593)

### Summary

Publish the Embedded Systems Roadmap walk-through article!

Bonus: add a new tag: `career`. Hopefully there are more articles
in the future that touch on continuous learning topics like this!

### Test Plan

 - [x] Run through publishing checklist

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Co-authored-by: geekigirlx <33341738+geekigirlx@users.noreply.github.com>

Author: gminn