docs(markdown): architecture README

Author: ploMP4

internal/markdown/README.md

@@ -0,0 +1,49 @@
+# Architecture
+
+```mermaid
+graph TB
+    subgraph "Markdown Package Architecture"
+        A[Input Markdown Text] --> B[MarkdownParser]
+        
+        subgraph "Parser Registry"
+            C[Parser A<br/>Priority: 1]
+            D[Parser B<br/>Priority: 2]
+            E[Parser N<br/>Priority: N]
+        end
+        
+        B --> F[Trigger-Based Parser Selection]
+        C --> F
+        D --> F
+        E --> F
+        
+        subgraph "Node Types"
+            G[Custom Node A]
+            H[Custom Node B]
+            I[GlamourNode<br/>Fallback]
+        end
+        
+        F --> G
+        F --> H
+        F --> I
+        
+        subgraph "Renderer Components"
+            J[Main Renderer]
+            K[Default Renderer For GlamourNode]
+            L[Custom Renderer For Node A]
+            M[Custom Renderer For Node B]
+        end
+        
+        G --> J
+        H --> J
+        I --> J
+        
+        J --> K
+        J --> L
+        J --> M
+        
+        N[Styled Terminal Output] 
+        K --> N
+        L --> N
+        M --> N
+    end
+```