fix link

Author: LiamConnors

_posts/plotly_js/3d/3d-surface/2018-10-09-surface-contours.html

@@ -6,7 +6,7 @@
 sitemap: false
 arrangement: horizontal
 markdown_content: |
-  Display and customize contour data for each axis using the `contours` attribute ([reference](plot.ly/javascript/reference/surface/#surface-contours)).
+  Display and customize contour data for each axis using the `contours` attribute ([reference](/javascript/reference/surface/#surface-contours)).
 
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