Replace og:image with 200x200 logo (#996)

Author: hugovk

_static/og-image-200x200.png

@@ -109,11 +109,11 @@
 # sphinxext-opengraph config
 ogp_site_url = "https://devguide.python.org/"
 ogp_site_name = "Python Developer's Guide"
-ogp_image = "_static/og-image.png"
+ogp_image = "_static/og-image-200x200.png"
 ogp_custom_meta_tags = [
-    '<meta property="og:image:width" content="1200">',
-    '<meta property="og:image:height" content="630">',
-    '<meta name="theme-color" content="#3776ab" />',
+    '<meta property="og:image:width" content="200">',
+    '<meta property="og:image:height" content="200">',
+    '<meta name="theme-color" content="#3776ab">',
 ]
 
 # Strip the dollar prompt when copying code