Merge pull request #5727 from mermaid-js/5726_doctype

Aligning doctype so that mermaid renders in the same way with or without it

packages/mermaid/src/styles.ts

@@ -70,6 +70,9 @@ const getStyles = (
     font-family: ${options.fontFamily};
     font-size: ${options.fontSize};
   }
+   & p {
+    margin: 0
+   }
 
   ${diagramStyles}