documentation: append quickstart page

docs/conf.py

@@ -36,6 +36,12 @@ extensions = [
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
 
+# The suffix of source filenames.
+source_suffix = ".rst"
+
+# The master toctree document.
+master_doc = "index"
+
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
 #
@@ -64,3 +70,14 @@ if on_rtd:
 
 # Output file base name for HTML help builder.
 htmlhelp_basename = 'multiusrdoc'
+
+# sphinx-notfound-page
+# https://github.com/readthedocs/sphinx-notfound-page
+notfound_context = {
+    'title': 'Page Not Found',
+    'body': '''
+<h1>Page Not Found</h1>
+<p>Sorry, we couldn't find that page.</p>
+<p>Try using the search box or go to the homepage.</p>
+''',
+}