Presentation material for inspiration showcases (#319)

* add presentation materials

* Update docs/user-guide/developer-content/inspiration-showcase/showcase.qmd

Co-authored-by: Erik van Sebille <erikvansebille@gmail.com>

* Fix Pixi caching in CI (#321)

* add presentation materials

* update with new slides on ours and theirs expectations

* re-render

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Co-authored-by: Erik van Sebille <erikvansebille@gmail.com>
Co-authored-by: Nick Hodgskin <36369090+VeckoTheGecko@users.noreply.github.com>

Author: 3 people