Add subsections to documentation navigation

- Add hierarchical subsections to Handlers (Basic, Intermediate, Advanced)
- Add hierarchical subsections to Advanced Features (UI Features, System Features, Data Handling)
- Add JavaScript to dynamically assign clean IDs to h3 headings for anchor links
- Add CSS styling for navigation subsections with proper indentation
- Fix parentheses balance issues in onerc.el functions

one.org

@@ -282,6 +282,8 @@ We strongly recommend that you follow the [[#/quick-start/][Quick start]] to see
 
 Handlers are Python functions that respond to WebSocket messages from the client. They contain your business logic and can render HTML, update the database, broadcast to multiple users, and more.
 
+*** Basic
+
 ** Your First Handler
 
 Let's start with the simplest possible handler. This handler will be called when a button is clicked and will update a section of the page.
@@ -426,6 +428,8 @@ def example(consumer, content):
     pass
 #+END_SRC
 
+*** Intermediate
+
 ** Auto-discovery
 
 Django LiveView automatically discovers handlers in ~liveview_components/~ directories within your installed apps:
@@ -577,6 +581,8 @@ HTML code:
 </div>
 #+END_SRC
 
+*** Advanced
+
 ** Updating the URL Without Page Reload
 
 Create SPA-like navigation by updating both content and the browser URL.
@@ -930,6 +936,8 @@ def send_notification(consumer, content):
 :NAVIGATOR-ACTIVE: docs
 :END:
 
+*** UI Features
+
 ** Intersection Observer (Infinite Scroll)
 
 Trigger functions when elements enter or exit the viewport:
@@ -1051,6 +1059,8 @@ def search_articles(consumer, content):
 
 Without debounce, typing "python" would send 6 requests (one per letter). With ~data-liveview-debounce="500"~, it sends only 1 request after the user stops typing for 500ms.
 
+*** System Features
+
 ** Middleware System
 
 Add middleware to run before handlers for authentication, logging, or rate limiting:
@@ -1086,6 +1096,8 @@ liveview_registry.add_middleware(auth_middleware)
 liveview_registry.add_middleware(logging_middleware)
 #+END_SRC
 
+*** Data Handling
+
 ** Script Execution
 
 Execute JavaScript code directly from your Python handlers.