refactor(render): filewriting in render pkg

pkg/render/fs.go

@@ -0,0 +1,32 @@
+package render
+
+import (
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+
+	"github.com/sh0rez/docsonnet/pkg/docsonnet"
+)
+
+func To(api, out string) error {
+	pkg, err := docsonnet.Load(api)
+	if err != nil {
+		return err
+	}
+
+	if err := os.MkdirAll(out, os.ModePerm); err != nil {
+		return err
+	}
+
+	log.Println("Rendering .md files")
+	data := Render(*pkg)
+	for k, v := range data {
+		if err := ioutil.WriteFile(filepath.Join(out, k), []byte(v), 0644); err != nil {
+			return err
+		}
+	}
+
+	log.Printf("Success! Rendered %v packages from '%s' to '%s'", len(data), api, out)
+	return nil
+}