urls: Add attribution page.

This records images we used from Creative Commons sources.

It's something of a placeholder for a nicer page.

templates/zerver/attribution.html

@@ -0,0 +1,31 @@
+{% extends "zerver/portico.html" %}
+{% set entrypoint = "landing-page" %}
+
+{% block title %}
+<title>Zulip: The best group chat for your business.</title>
+{% endblock %}
+
+{% block customhead %}
+<meta name="viewport" content="width=device-width, initial-scale=1.0" />
+{% endblock %}
+
+{% block portico_content %}
+
+{% include 'zerver/landing_nav.html' %}
+
+<div class="portico-landing why-page">
+    <div class="hero empty-hero"></div>
+    <div class="main">
+        <div class="padded-content">
+            <h1>Attributions</h1>
+            <ul>
+                <li>
+                    <b>On <a href="/for/companies">/for/companies</a> page:</b>
+                    <img alt="" src="/static/images/landing-page/companies/software-engineer.svg" />
+                    <p>"<a href="https://iconscout.com/illustration/software-engineer-2043023">Software engineer Illustration</a>" By <a href="https://iconscout.com/contributors/delesign/illustrations">Delesign Graphic</a> is licensed under <a href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a>.</p>
+                </li>
+            </ul>
+        </div>
+    </div>
+</div>
+{% endblock %}

templates/zerver/footer.html

@@ -128,8 +128,9 @@
         <h3>{{ _("About us") }}</h3>
         <ul>
             <li><a href="/team/">{{ _("Team") }}</a> &amp; <a href="/history/">{{ _("History") }}</a></li>
-            <li><a href="/jobs/">{{ _("Jobs") }}</a></li>
             <li><a href="https://twitter.com/zulip/">Twitter</a></li>
+            <li><a href="/jobs/">{{ _("Jobs") }}</a></li>
+            <li><a href="/attribution">Website attributions</a></li>
             <li><a href="https://github.com/sponsors/zulip">{{ _("Sponsor Zulip") }}</a></li>
         </ul>
     </div>

zerver/tests/test_docs.py

@@ -166,6 +166,7 @@ class DocPageTest(ZulipTestCase):
         self._test("/for/companies/", "in a company")
         self._test("/for/communities/", "Zulip for communities")
         self._test("/security/", "TLS encryption")
+        self._test("/attribution/", "Attributions")
         self._test("/devlogin/", "Normal users", landing_page=False)
         self._test("/devtools/", "Useful development URLs")
         self._test("/errors/404/", "Page not found")

zproject/urls.py

@@ -606,6 +606,7 @@ i18n_urls = [
     path(
         "developer-community/", landing_view, {"template_name": "zerver/developer-community.html"}
     ),
+    path("attribution/", landing_view, {"template_name": "zerver/attribution.html"}),
     path("team/", team_view),
     path("history/", landing_view, {"template_name": "zerver/history.html"}),
     path("why-zulip/", landing_view, {"template_name": "zerver/why-zulip.html"}),