Use sphinxext-opengraph to generate OpenGraph metadata (GH-99931)

(cherry picked from commit f49c735e52)

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>

Doc/conf.py

@@ -13,9 +13,25 @@ sys.path.append(os.path.abspath('includes'))
 # General configuration
 # ---------------------
 
-extensions = ['sphinx.ext.coverage', 'sphinx.ext.doctest',
-              'pyspecific', 'c_annotations', 'escape4chm',
-              'asdl_highlight', 'peg_highlight', 'glossary_search']
+extensions = [
+    'asdl_highlight',
+    'c_annotations',
+    'escape4chm',
+    'glossary_search',
+    'peg_highlight',
+    'pyspecific',
+    'sphinx.ext.coverage',
+    'sphinx.ext.doctest',
+]
+
+# Skip if downstream redistributors haven't installed it
+try:
+    import sphinxext.opengraph
+except ImportError:
+    pass
+else:
+    extensions.append('sphinxext.opengraph')
+
 
 doctest_global_setup = '''
 try:
@@ -109,7 +125,7 @@ html_additional_pages = {
 html_use_opensearch = 'https://docs.python.org/' + version
 
 # Additional static files.
-html_static_path = ['tools/static']
+html_static_path = ['_static', 'tools/static']
 
 # Output file base name for HTML help builder.
 htmlhelp_basename = 'python' + release.replace('.', '')
@@ -234,3 +250,13 @@ linkcheck_ignore = [r'https://bugs.python.org/(issue)?\d+']
 # Relative filename of the data files
 refcount_file = 'data/refcounts.dat'
 stable_abi_file = 'data/stable_abi.dat'
+
+# sphinxext-opengraph config
+ogp_site_url = 'https://docs.python.org/3/'
+ogp_site_name = 'Python documentation'
+ogp_image = '_static/og-image.png'
+ogp_custom_meta_tags = [
+    '<meta property="og:image:width" content="200">',
+    '<meta property="og:image:height" content="200">',
+    '<meta name="theme-color" content="#3776ab">',
+]