redirect to the 404 page (#16287)

* redirect to the 404 so that people are at least on the website

* improve 404 documentation

* nudge ci

Author: ThomasDelteil

docs/static_site/src/.htaccess

@@ -22,3 +22,7 @@ RewriteCond %{REQUEST_URI} !\/$
 RewriteCond %{REQUEST_FILENAME} -d
 RewriteCond %{REQUEST_FILENAME}/index.html -f
 RewriteRule ^(.*) $1/index.html [NC,L]
+
+
+# 404
+ErrorDocument 404 /404.html

docs/static_site/src/404.html

@@ -19,6 +19,12 @@
 <div class="container">
   <h1>404</h1>
 
-  <p><strong>Page not found :(</strong></p>
-  <p>The requested page could not be found.</p>
+  <p><strong>Page not found :'(</strong></p>
+
+  <p><b>Due to a recent redesign of the website, some items have moved</b>
+    We're working towards adding redirects. Useful links:</p>
+  <div style="background-color:white;">
+    <li><a href="/api/python/docs/tutorials/">Python Tutorials</a></li>
+    <li><a href="/api/python/docs/api/">Python API Documentation</a></li>
+  </div>
 </div>