Update gallery.yaml (#1120)

* Update gallery.yaml

Added Pastas to the example gallery. Thanks for developing this theme!

* Add Pastas

---------

Co-authored-by: Rambaud Pierrick <[email protected]>

Author: raoulcollenteur

docs/examples/gallery.md

@@ -38,4 +38,6 @@ Thanks for your support!
   link: https://www.megengine.org.cn/doc/stable/en/index.html
 - title: PyVista
   link: https://docs.pyvista.org
+- title: Pastas
+  link: https://pastas.readthedocs.io/
 ```