feat: new plantuml

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "plantuml.server": "http://www.plantuml.com/plantuml"
+}

test.md

@@ -0,0 +1,23 @@
+<h1>项目名称</h1>
+
+``` plantuml
+@startuml
+abstract        abstract
+abstract class  "abstract class"
+annotation      annotation
+circle          circle
+()              circle_short_form
+class           class
+class           class_stereo  <<stereotype>>
+diamond         diamond
+<>              diamond_short_form
+entity          entity
+enum            enum
+exception       exception
+interface       interface
+metaclass       metaclass
+protocol        protocol
+stereotype      stereotype
+struct          struct
+@enduml
+```