fix: update flowchart for 2621. sleep

Author: nutkiattisak

Diff for: 2621. sleep/README.md

@@ -0,0 +1,14 @@
+```mermaid
+flowchart TD
+  A(Start) --> B[Create Promise]
+  B --> C[Set timeout]
+  C --> D[Wait for milliseconds]
+  D --> E[Resolve Promise]
+  E --> F(End)
+
+  style A fill:#52bc94, stroke:#ffffff, stroke-width:1px, color:#ffffff
+  style B fill:#101841, stroke:#ffffff, stroke-width:1px, color:#ffffff
+  style C fill:#101841, stroke:#ffffff, stroke-width:1px, color:#ffffff
+  style D fill:#101841, stroke:#ffffff, stroke-width:1px, color:#ffffff
+  style E fill:#101841, stroke:#ffffff, stroke-width:1px, color:#ffffff
+  style F fill:#d14243, stroke:#ffffff, stroke-width:1px, color:#ffffff