style(docs): enhance CSS for better readability and maintainability

Improve the styling of the documentation by adding more space at the
bottom of the page and overriding the minimum height for content to
ensure full viewport height. Mark external links with an icon for
better user experience. Simplify and consolidate CSS rules for
consistency and easier maintenance. Adjust heading padding for better
visual hierarchy. These changes aim to enhance the overall look and
feel of the documentation, making it more user-friendly and visually
appealing.

chore(mkdocs.yml): update mkdocs configuration for better documentation generation

Reorganize the mkdocs.yml file to improve the configuration of plugins
and extensions. Move the autorefs plugin to a more logical position
and update its settings for resolving closest references. Adjust
mkdocstrings settings to show category headings and merge __init__
into class documentation. Modify signature and docstring settings for
better readability. These changes aim to improve the documentation
generation process, making it more efficient and the output more
informative.

Author: kzndotsh

docs/content/assets/stylesheets/extra.css

@@ -4,6 +4,17 @@
   max-width: 75rem;
 }
 
+/* More space at the bottom of the page. */
+.md-main__inner {
+  margin-bottom: 1.5rem;
+}
+
+
+/* override md-content min-height */
+.md-content {
+  min-height: 100vh;
+}
+
 /* Shrink header and footer to the content size*/
 .md-grid {
   /* Default 61rem */
@@ -178,4 +189,16 @@
   img[src$="#gh-light-mode-only"] {
     display: none;
   }
+}
+
+/* Mark external links as such (also in nav) */
+a.external:hover::after,
+a.md-nav__link[href^="https:"]:hover::after {
+  /* https://primer.style/octicons/link-external-16 */
+  background-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><path fill="rgb(233, 235, 252)" d="M10.604 1h4.146a.25.25 0 01.25.25v4.146a.25.25 0 01-.427.177L13.03 4.03 9.28 7.78a.75.75 0 01-1.06-1.06l3.75-3.75-1.543-1.543A.25.25 0 0110.604 1zM3.75 2A1.75 1.75 0 002 3.75v8.5c0 .966.784 1.75 1.75 1.75h8.5A1.75 1.75 0 0014 12.25v-3.5a.75.75 0 00-1.5 0v3.5a.25.25 0 01-.25.25h-8.5a.25.25 0 01-.25-.25v-8.5a.25.25 0 01.25-.25h3.5a.75.75 0 000-1.5h-3.5z"></path></svg>');
+  height: 0.8em;
+  width: 0.8em;
+  margin-left: 0.2em;
+  content: ' ';
+  display: inline-block;
 }