docs: add mkdocs, update links, add architecture documentation

docs/content/assets/css/custom.css

@@ -0,0 +1,23 @@
+/* Full width content */
+.md-content {
+  max-width: 100% !important;
+}
+
+.md-main__inner {
+  max-width: 100% !important;
+}
+
+.md-grid {
+  max-width: 100% !important;
+}
+
+/* Ensure content area uses full width while keeping readable line length */
+.md-content__inner {
+  max-width: 100%;
+}
+
+/* Adjust container padding for better full-width experience */
+.md-container {
+  max-width: 100%;
+}
+