Add a link to the Large Scale SIG docs

The Large Scale SIG has started to publish their documentation at [0],
migrating content from the Wiki[1]. Add a link to the main landing page
and also add the repo to the _IGNORED_REPOS list in www-generator.py,
since it doesn't use the /latest/ patch as it is branchless and not
release-specific.

[0] https://docs.openstack.org/large-scale/index.html
[1] https://wiki.openstack.org/wiki/Large_Scale_SIG

Change-Id: Ie7f297615d746f36f24e63ee3f25b4938e6f45e3

tools/www-generator.py

@@ -429,6 +429,7 @@ _IGNORED_REPOS = [
     'openstack/ha-guide',
     'openstack/arch-design',
     'openstack/project-team-guide',
+    'openstack/large-scale',
 ]
 
 # List of infra repos that publish to the normal location (/REPO/) and

www/yoga/index.html

@@ -74,6 +74,8 @@
         <p>The Extended Maintenance SIG manages the existing stable branches</p>
         <a href="/self-healing-sig/">Self-healing SIG documentation</a>
         <p>Self-healing use cases and implementation details</p>
+        <a href="/large-scale/">Large Scale SIG documentation</a>
+        <p>The journey of running OpenStack at large scale</p>
       </div>
       <div class="docs-link-sections">
         <h3 id="doc-contrib-guides"><i class="fa fa-pencil"></i>Contributor Guides</h3>

www/zed/index.html

@@ -74,6 +74,8 @@
         <p>The Extended Maintenance SIG manages the existing stable branches</p>
         <a href="/self-healing-sig/">Self-healing SIG documentation</a>
         <p>Self-healing use cases and implementation details</p>
+        <a href="/large-scale/">Large Scale SIG documentation</a>
+        <p>The journey of running OpenStack at large scale</p>
       </div>
       <div class="docs-link-sections">
         <h3 id="doc-contrib-guides"><i class="fa fa-pencil"></i>Contributor Guides</h3>