TEMP point to preview build to check the Facebook preview

Author: hugovk

conf.py

@@ -107,7 +107,7 @@
 
 # sphinxext-opengraph config
 ogp_site_url = "https://devguide.python.org/"
-ogp_image = "https://devguide.python.org/_static/og-image.png"
+ogp_image = "https://cpython-devguide--953.org.readthedocs.build/_static/og-image.png"
 ogp_custom_meta_tags = [
     '<meta property="og:image:width" content="1200">',
     '<meta property="og:image:height" content="630">',