[ENH] Improving Documentation webpage (#1150)

This PR is intended to change the documentation (jupyter book), small
style changes as well as content and organisation of the documentation.

Co-authored-by: Arnau Jimenez <arnau.jimenez@zeiss.com>

docs/_config.yml

@@ -50,7 +50,7 @@ parse:
 #######################################################################################
 # HTML-specific settings
 html:
-  favicon                   : ""  # A path to a favicon image
+  favicon                   : "_static/images/tianshou-favicon.png"  # A path to a favicon image
   use_edit_page_button      : false  # Whether to add an "edit this page" button to pages. If `true`, repository information in repository: must be filled in
   use_repository_button     : false  # Whether to add a link to your repository button
   use_issues_button         : false  # Whether to add an "open an issue" button

docs/_static/css/style.css

@@ -50,6 +50,13 @@ h1, h2, .rst-content .toctree-wrapper p.caption, h3, h4, h5, h6, legend, p.capti
     display: none;
 }
 
+@media (min-width: 960px) {
+    .bd-page-width {
+        max-width: none !important;
+    }
+}
+
+
 @media screen and (max-width: 768px) {
     .wy-side-nav-search>a img.logo {
         height: 60px;