Fix sphinx documentation style

We have updated our used sphinx and alabaster versions and they had some major
breaking changes in the style and our current documentation looks a bit off.
These changes ensures that we have the same style like before.

Author: Garados007

docu/sphinx/source/_static/custom.css

@@ -1,3 +1,16 @@
-dl.function:not(:last-child) {
-  margin-bottom: 3em;
-}
+dl.function:not(:last-child) {
+  margin-bottom: 3em;
+}
+
+@media screen and (max-width: 940px) {
+  div.document {
+    display: flex;
+    flex-direction: column-reverse;
+  }
+
+  div.document div.sphinxsidebar {
+    margin: -20px -30px 20px -30px;
+    width: unset;
+    left: 0;
+  }
+}

docu/sphinx/source/conf.py

@@ -109,7 +109,6 @@ def getDocRoot():
     'github_repo': 'igortest',
     'github_banner': True,
     'show_powered_by': False,
-    'page_width' : '90%',
 }
 
 html_context = {