some more comments

documentation/FEATURES.md

@@ -107,6 +107,31 @@ $$
 
 📄 **See the [MATHJAX](MATHJAX.md) note for more examples and syntax reference.**
 
+## 📊 Mermaid Diagrams
+
+### Visual Diagrams
+- **Flowcharts** - Process flows and decision trees
+- **Sequence diagrams** - System interactions over time
+- **Class diagrams** - UML class relationships
+- **State diagrams** - State machines and transitions
+- **Gantt charts** - Project timelines
+- **Pie charts** - Data visualization
+- **Git graphs** - Branch and commit history
+- **Theme support** - Adapts to your theme
+
+### Example
+````markdown
+```mermaid
+graph TD
+    A[Start] --> B{Is it working?}
+    B -->|Yes| C[Great!]
+    B -->|No| D[Debug]
+    D --> B
+```
+````
+
+📄 **See the [MERMAID](MERMAID.md) note for diagram examples and syntax reference.**
+
 ## ⚡ Keyboard Shortcuts
 
 | Windows/Linux | Mac | Action |