chore: initial gomark plugin (#1678)

chore: initial gomark folder

plugin/gomark/ast/node.go

@@ -0,0 +1,12 @@
+package ast
+
+func NewNode(tp, text string) *Node {
+	return &Node{
+		Type: tp,
+		Text: text,
+	}
+}
+
+func (n *Node) AddChild(child *Node) {
+	n.Children = append(n.Children, child)
+}