workaround for 404 error pages assets and sitemap links (#1069)

RTD is still working on making MkDocs fully integrated. Some changes will be done during Google Summer of Code but this is a workaround to have 404 and sitemaps working before we have these fixes.
Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

.gitignore

@@ -25,3 +25,4 @@ target/
 tmp/
 build/
 out/
+site/

docs/custom_theme/404.html

@@ -0,0 +1,18 @@
+{% extends "main.html" %}
+
+<!-- Content block -->
+{% block content %}
+
+<p style="text-align: center;font-size: 3em"><i class="md-icon">account_balance</i></p>
+<h1 id="404-page-not-found" style="text-align: center">404</h1>
+<p style="text-align: center"><strong>Deity not found in the Pantheon</strong></p>
+<p style="text-align: center">
+  Try the <a href="/">homepage</a>, or use the search field on the top of this page.
+</p>
+<p style="text-align: center">
+  If you think we made a mistake and deleted a page that should be here, then please tell us on
+  <a href="{{config.extra.support.gitter}}">{{config.site_name}} Gitter channel</a> or create an issue in
+  <a href="{{ config.repo_url + '/issues' }}">Pantheon Github repository</a>.
+</p>
+
+{% endblock %}

docs/custom_theme/partials/footer.html

@@ -23,9 +23,9 @@
 {% import "partials/language.html" as lang with context %}
 
 <div class="feedback md-typeset">
-      Questions or feedback? You can discuss issues and obtain free support on <a href="{{config.extra.support.gitter}}">Pegasys Pantheon Gitter room</a>.
+  Questions or feedback? You can discuss issues and obtain free support on <a href="{{config.extra.support.gitter}}">{{config.site_name}} Gitter channel</a>.
-      <br/>
+  <br/>
-      For paid professional support by <a href="https://pegasys.tech/">PegaSys</a>, contact us at <a href="mailto:{{config.extra.support.email}}">{{config.extra.support.email}}</a>
+  For paid professional support by <a href="{{config.extra.support.pegasys_website}}">PegaSys</a>, contact us at <a href="mailto:{{config.extra.support.email}}">{{config.extra.support.email}}</a>
 </div>
 
 <!-- Application footer -->

docs/requirements.txt

@@ -1,6 +1,6 @@
 mkdocs>=1.0
 pymdown-extensions==6.0
-mkdocs-material>=3.1
+mkdocs-material>=4.0
 Markdown==3.0.1
 markdown-fenced-code-tabs==1.0.5
 markdown-include==0.5.1

mkdocs.yml

@@ -11,7 +11,7 @@
 
 # Project information
 site_name: Pantheon
-site_url: https://docs.pantheon.pegasys.tech/
+site_url: https://docs.pantheon.pegasys.tech/en/stable/
 site_description: Pantheon Java Ethereum client documentation.
 site_author: Pantheon community
 copyright: Pantheon and its documentation are licensed under Apache 2.0 license /
@@ -22,6 +22,7 @@ extra:
   support:
     gitter: https://gitter.im/PegaSysEng/pantheon
     email: support@pegasys.tech
+    pegasys_website: https://pegasys.tech/
   google:
     analytics_id: 'UA-117921923-2'
     site_verification: 'za1cLzyS6LXDGO-pMzvfQdYTZ0Zc67uZtY0asA4YXZ0'
@@ -29,7 +30,7 @@ extra:
 
 # Repository
 repo_name: PegaSysEng/pantheon
-repo_url: https://github.com/PegaSysEng/pantheon
+repo_url: https://github.com/PegaSysEng/pantheon/
 
 theme:
     name: material