WIP: Render database schema using Mermaid.js

Still need to:
* Move mermaid.js to static files
* Make template for mermaid wrapper
* Create new page for SQL viewer then add explorer

templates/settings.html

@@ -181,6 +181,8 @@
         </form>
 
     </div>
+
+    <div hx-get="{{ url_for('get_sql_schema') }}" hx-trigger="load"></div>
 </div>
 
 {% endblock %}