Add pixi example (#12155)
Pixi is a modern package manager for the conda ecosystem. It's much
faster than conda/mamba and also supports lockfiles natively.
You can install pixi via asdf
(https://github.com/asdf-vm/asdf-plugins/blob/master/plugins/pixi) so
the usage within mkdocs should be fairly straightforward.
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:books: Documentation previews :books:
- User's documentation (`docs`):
https://docs--12155.org.readthedocs.build/12155/
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- Developer's documentation (`dev`):
https://dev--12155.org.readthedocs.build/12155/
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Co-authored-by: Eric Holscher <eric@ericholscher.com>
