feat: add docgen program

cmd/docgen/docgen.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"fmt"
+	"go/doc"
+	"go/parser"
+	"go/token"
+)
+
+func main() {
+	fset := token.NewFileSet()
+
+	d, err := parser.ParseDir(fset, "./", nil, parser.ParseComments)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	for _, f := range d {
+		p := doc.New(f, "./", 0)
+
+		for _, t := range p.Funcs {
+			fmt.Println("	type", t.Name)
+			fmt.Println("		docs:", t.Doc)
+		}
+	}
+}