Banner pointing people to the contributing guide to help us

Author: humitos

conf.py

@@ -33,10 +33,33 @@
 
 os.system('mkdir -p cpython/locales/es/')
 os.system('ln -nfs `pwd` cpython/locales/es/LC_MESSAGES')
+os.system('ln -nfs `pwd`/CONTRIBUTING.rst cpython/Doc/CONTRIBUTING.rst')
 
 gettext_compact = False
 locale_dirs = ['../locales', 'cpython/locales']  # relative to the sourcedir
 
 def setup(app):
+
+    def add_contributing_banner(app, doctree):
+        """
+        Insert a banner at the top of the index.
+
+        This way, we can easily communicate people to help with the translation,
+        pointing them to different resources.
+        """
+        from docutils import nodes, core
+
+        message = '¡Ayúdanos a traducir la documentación oficial de Python al Español! ' \
+        f'Más información en `Como contribuir </es/{version}/CONTRIBUTING.html>`_'
+
+        paragraph = core.publish_doctree(message)[0]
+        banner = nodes.warning(ids=['contributing-banner'])
+        banner.append(paragraph)
+
+        for document in doctree.traverse(nodes.document):
+            document.insert(0, banner)
+
     # Change the sourcedir programmatically because Read the Docs always call it with `.`
     app.srcdir = 'cpython/Doc'
+
+    app.connect('doctree-read', add_contributing_banner)