Update the link for PyVista (#686)

Author: banesullivan

content/en/tabcontents.yaml

@@ -168,7 +168,7 @@ params:
     - url: https://seaborn.pydata.org
       img: /images/content_images/v_seaborn.png
       alttext:  A pairplot of two types of graph, a plot-graph and a frequency graph made in seaborn"
-    - url: https://docs.pyvista.org/examples/index.html
+    - url: https://docs.pyvista.org/
       img: /images/content_images/v_pyvista.png
       alttext:  A 3D volume rendering made in PyVista.
     - url: https://napari.org

content/ja/tabcontents.yaml

@@ -201,7 +201,7 @@ params:
         img: /images/content_images/v_seaborn.png
         alttext: 2種類のグラフによるペアプロット。seabornで作られたプロットと周波数グラフ"
       - 
-        url: https://docs.pyvista.org/examples/index.html
+        url: https://docs.pyvista.org/
         img: /images/content_images/v_pyvista.png
         alttext: PyVista製の3Dボリュームレンダリング
       - 

content/pt/tabcontents.yaml

@@ -201,7 +201,7 @@ params:
         img: /images/content_images/v_seaborn.png
         alttext: A plot duplo com dois tipos de gráficos, um plot-graph e um gráfico de frequência feitos no seaborn
       - 
-        url: https://docs.pyvista.org/examples/index.html
+        url: https://docs.pyvista.org/
         img: /images/content_images/v_pyvista.png
         alttext: Uma renderização de volume 3D feita no PyVista.
       -